CHAPTER I. THE LORD'S DAY -- THE WORSHIP OF THE APOSTOLIC CHURCH -- ITS SYMBOLIC ORDINANCES AND ITS DISCIPLINE. To the primitive disciples the day on which our Lord rose from the grave was a crisis of intense excitement. The crucifixion had cast a dismal cloud over their prospects; for, immediately before, when He entered Jerusalem amidst the hosannahs of the multitude, they had probably anticipated that He was about to assert His sovereignty as the Messiah: yet, when His body was committed to the tomb, they did not at once sink into despair; and, though filled with anxiety, they ventured to indulge a hope that the third day after His demise would be signalised by some new revelation. [210:1] The report of those who were early at the sepulchre at first inspired the residue of the disciples with wonder and perplexity; [210:2] but, as the proofs of His resurrection multiplied, they became confident and joyful. Ever afterwards the first day of the week was observed by them as the season of holy convocation. [211:1] Those members of the Apostolic Church who had been originally Jews, continued for some time to meet together also on the Saturday; but, what was called "The Lord's Day," [211:2] was regarded by all as sacred to Christ. It has often been asserted that, during His own ministry, our Saviour encouraged His disciples to violate the Sabbath, and thus prepared the way for its abolition. But this theory is as destitute of foundation as it is dangerous to morality. Even the ceremonial law continued to be binding until Jesus expired upon the cross; and meanwhile He no doubt felt it to be His duty to attend to every jot and tittle of its appointments. [211:3] Thus, it became Him "to fulfil all righteousness." [211:4] He is at pains to shew that the acts of which the Pharisees complained as breaches of the Sabbath could be vindicated by Old Testament authority; [211:5] and that these formalists "condemned the guiltless," [211:6] when they denounced the disciples as doing that which was unlawful. Jesus never transgressed either the letter or the spirit of any commandment pertaining to the holy rest; but superstition had added to the written law a multitude of minute observances; and every Israelite was at perfect liberty to neglect any or all of these frivolous regulations. The Great Teacher never intimated that the Sabbath was a ceremonial ordinance which was to cease with the Mosaic ritual. It was instituted when our first parents were in Paradise; [211:7] and the precept enjoining its remembrance, being a portion of the Decalogue, [212:1] is of perpetual obligation. Hence, instead of regarding it as a merely Jewish institution, Christ declares that it "was made for MAN," [212:2] or, in other words, that it was designed for the benefit of the whole human family. Instead of anticipating its extinction along with the ceremonial law, He speaks of its existence after the downfal of Jerusalem. When He announces the calamities connected with the ruin of the holy city, He instructs His followers to pray that the urgency of the catastrophe may not deprive them of the comfort of the ordinances of the sacred rest. "Pray ye," said he, "that your flight be not in the winter, neither on the Sabbath-day." [212:3] And the prophet Isaiah, when describing the ingathering of the Gentiles and the glory of the Church in the times of the gospel, mentions the keeping of the Sabbath as characteristic of the children of God. "The sons of the stranger," says he, "that join themselves to the Lord to serve him, and to love the name of the Lord, to be his servants, every one that keepeth the Sabbath from polluting it, and taketh hold of my covenant -- even them I will I bring to my holy mountain, and make them joyful in my house of prayer; their burnt-offerings and their sacrifices shall be accepted upon mine altar: [212:4] for mine house shall be called an house of prayer for all people." [212:5] But when Jesus declared that "the Son of Man is Lord also of the Sabbath," [212:6] He unquestionably asserted His right to alter the circumstantials of its observance. He accordingly abolished its ceremonial worship, gave it a new name, and changed the day of its celebration. He signalised the first day of the week by then appearing once and again to His disciples after His resurrection, [212:7] and by that Pentecostal outpouring of the Spirit [213:1] which marks the commencement of a new era in the history of redemption. As the Lord's day was consecrated to the Lord's service, [213:2] the disciples did not now neglect the assembling of themselves together; [213:3] and the apostle commanded them at this holy season to set apart a portion of their gains for religious purposes. [213:4] It was most fitting that the first day of the week should be thus distinguished under the new economy; for the deliverance of the Church is a more illustrious achievement than the formation of the world; [213:5] and as the primeval Sabbath commemorated the rest of the Creator, the Christian Sabbath reminds us of the completion of the work of the Redeemer. "There remaineth, therefore, the keeping of a Sabbath [213:6] to the people of God, for he that is entered into his rest, he also hath ceased from his own works, as God did from his." [213:7] As many of the converts from Judaism urged the circumcision of their Gentile brethren, they were likewise disposed to insist on their observance of the Hebrew festivals. The apostles, at least for a considerable time, did not deem it expedient positively to forbid the keeping of such days; but they required that, in matters of this nature, every one should be left to his own discretion. "One man," says Paul, "esteemeth one day above another; another esteemeth every day alike. Let every man be fully persuaded in his own mind." [213:8] It is obvious that the Lord's day is not included in this compromise; for from the morning of the resurrection there appears to have been no dispute as to its claims, and its very title attests the general recognition of its authority. The apostle can refer only to days which were typical and ceremonial. Hence he says elsewhere -- "Let no man judge you in meat, or in drink, or in respect of an holyday, or of the new moon, or of the Sabbath days -- which are a shadow of things to come, but the body is of Christ." [214:1]

Though the New Testament furnishes no full and circumstantial description of the worship of the Christian Church, it makes such incidental allusions to its various parts, as enable us to form a pretty accurate idea of its general character. Like the worship of the synagogue [214:2] it consisted of prayer, singing, reading the Scriptures, and expounding or preaching. Those who joined the Church, for several years after it was first organized, were almost exclusively converts from Judaism, and when they embraced the Christian faith, they retained the order of religious service to which they had been hitherto accustomed; but by the recognition of Jesus Christ as the Messiah of whom the law and the prophets testified, their old forms were inspired with new life and significance. At first the heathen did not challenge the distinction between the worship of the synagogue and the Church; and thus it was, as has already been intimated, that for a considerable portion of the first century, the Christians and the Jews were frequently confounded.

It has often been asserted, that the Jews had a liturgy when our Lord ministered in their synagogues; but the proof adduced in support of this statement is far from satisfactory; and their prayers which are still extant, and which are said to have been then in use, must obviously have been written after the destruction of Jerusalem. [215:1] It is, however, certain that the Christians in the apostolic age were not restricted to any particular forms of devotion. The liturgies ascribed to Mark, James, and others, are unquestionably the fabrications of later times; [215:2] and had any of the inspired teachers of the gospel composed a book of common prayer, it would, of course, have been received into the canon of the New Testament. Our Lord taught His disciples to pray, and supplied them with a model to guide them in their devotional exercises; [215:3] but there is no evidence whatever that, in their stated services, they constantly employed the language of that beautiful and comprehensive formulary. The very idea of a liturgy was altogether alien to the spirit of the primitive believers. They were commanded to give thanks "in everything," [215:4] to pray "always with all prayer and supplication in the spirit," [215:5] and to watch thereunto "with all perseverance and supplication for all saints;" [215:6] and had they been limited to a form, they would have found it impossible to comply with these admonitions. Their prayers were dictated by the occasion, and varied according to passing circumstances. Some of them which have been recorded, [215:7] had a special reference to the occurrences of the day, and could not have well admitted of repetition. In the apostolic age, when the Spirit was poured out in such rich effusion on the Church, the gift, as well as the grace, of prayer was imparted abundantly, so that a liturgy would have been deemed superfluous, if not directly calculated to freeze the genial current of devotion.

Singing, in which none but Levites were permitted to unite, [216:1] and which was accompanied by instrumental music, constituted a prominent part of the temple service. The singers occupied an elevated platform adjoining the court of the priests; [216:2] and it is somewhat doubtful whether, in that position, they were distinctly heard by the majority of the worshippers within the sacred precincts. [216:3] As the sacrifices, offerings, and other observances of the temple, as well as the priests, the vestments, and even the building itself, had an emblematic meaning, [216:4] it would appear that the singing, intermingled with the music of various instruments of sound, was also typical and ceremonial. It seems to have indicated that the tongue of man cannot sufficiently express the praise of the King Eternal, and that all things, animate and inanimate, owe Him a revenue of glory. The worship of the synagogue was more simple. Its officers had, indeed, trumpets and cornets, with which they published their sentences of excommunication, and announced the new year, the fasts, and the Sabbath; [216:5] but they did not introduce instrumental music into their congregational services. The early Christians followed the example of the synagogue; and when they celebrated the praises of God "in psalms, and hymns, and spiritual songs," [216:6] their melody was "the fruit of the lips." [216:7] For many centuries after this period, the use of instrumental music was unknown in the Church. [217:1]

The Jews divided the Pentateuch and the writings of the Prophets into sections, one of which was read every Sabbath in the synagogue; [217:2] and thus, in the place set apart to the service of the God of Israel, His own will was constantly proclaimed. The Christians bestowed equal honour on the holy oracles; for in their solemn assemblies, the reading of the Scriptures of the Old and New Testament formed a part of their stated worship. [217:3] At the close of this exercise, one or more of the elders edified the congregation, either by giving a general exposition of the passage read, or by insisting particularly on some point of doctrine or duty which it obviously inculcated. If a prophet was present, he, too, had now an opportunity of addressing the auditory. [217:4]

As apostolic Christianity aimed to impart light to the understanding, its worship was uniformly conducted in the language of the people. It, indeed, attested its divine origin by miracles, and it accordingly enabled some to speak in tongues in which they had never been instructed; but it permitted such individuals to exercise their gifts in the church only when interpreters were present to translate their communications. [217:5] Whilst the gift of tongues, possessed by so many of the primitive disciples, must have attracted the attention of the Gentile as well as of the Jewish literati, it must also have made a powerful impression on the popular mind, more especially in large cities; for in such places there were always foreigners to whom these strange utterances would be perfectly intelligible, and for whom a discourse delivered in the speech of their native country would have peculiar charms. But in the worship of the primitive Christians there was no attempt, in the way of embellishment or decoration, to captivate the senses. The Church had no gorgeous temples, no fragrant incense, [218:1] no splendid vestments. For probably the whole of the first century, she celebrated her religious ordinances in private houses, [218:2] and her ministers officiated in their ordinary costume. John, the forerunner of our Saviour, "had his raiment of camel's hair, and a leathern girdle about his loins;" [218:3] but perhaps few of the early Christian preachers were arrayed in such coarse canonicals.

The Founder of the Christian religion instituted only two symbolic ordinances -- Baptism and the Lord's Supper. [218:4] It is universally admitted that, in the apostolic age, baptism was dispensed to all who embraced the gospel; but it has been much disputed whether it was also administered to the infant children of the converts. The testimony of Scripture on the subject is not very explicit; for, as the ordinance was in common use amongst the Jews, [218:5] a minute description of its mode and subjects was, perhaps, deemed unnecessary by the apostles and evangelists. When an adult heathen was received into the Church of Israel, it is well known that the little children of the proselyte were admitted along with him; [219:1] and as the Christian Scriptures no where forbid the dispensation of the rite to infants, it may be presumed that the same practice was observed by the primitive ministers of the gospel. This inference is emphatically corroborated by the fact that, of the comparatively small number of passages in the New Testament which treat of its administration, no less than five refer to the baptism of whole households. [219:2] It is also worthy of remark that these five cases are not mentioned as rare or peculiar, but as ordinary specimens of the method of apostolic procedure. It is not, indeed, absolutely certain that there was an infant in any of these five households; but it is, unquestionably, much more probable that they contained a fair proportion of little children, than that every individual in each of them had arrived at years of maturity, and that all these adults, without exception, at once participated in the faith of the head of the family, and became candidates for baptism.

In the New Testament faith is represented as the grand qualification for baptism; [219:3] but this principle obviously applies only to all who are capable of believing; for in the Word of God faith is also represented as necessary to salvation, [219:4] and yet it is generally conceded that little children may be saved. Under the Jewish dispensation infants were circumcised, and were thus recognised as interested in the divine favour, so that, if they be excluded from the rite of baptism, it follows that they occupy a worse position under a milder and more glorious economy. But the New Testament forbids us to adopt such an inference. It declares that infants should be "suffered to come" to the Saviour; [219:5] it indicates that baptism supplies the place of circumcision, for it connects the gospel institution with "the circumcision of Christ;" [220:1] it speaks of children as "saints" and as "in the Lord," [220:2] and, of course, as having received some visible token of Church membership; and it assures them that their sins are forgiven them "for His name's sake." [220:3] The New Testament does not record a single case in which the offspring of Christian parents were admitted to baptism on arriving at years of intelligence; but it tells of the apostles exhorting the men of Judea to repent and to submit to the ordinance, inasmuch as it was a privilege proffered to them and to their children. [220:4] Nay more, Paul plainly teaches that the seed of the righteous are entitled to the recognition of saintship; and that, even when only one of the parents is a Christian, the offspring do not on that account forfeit their ecclesiastical inheritance. "The unbelieving husband," says he, "is sanctified by the wife, and the unbelieving wife is sanctified by the husband, else were your children unclean, but now are they holy." [220:5] This passage demonstrates that the Apostolic Church recognised the holiness of infants, or in other words, that it admitted them to baptism.

The Scriptures furnish no very specific instructions as to the mode of baptism; and it is probable that, in its administration, the primitive heralds of the gospel did not adhere to a system of rigid uniformity. [220:6] Some have asserted that the Greek word translated baptize, [220:7] in our authorised version, always signifies immerse, but it has been clearly shewn [221:1] that this statement is inaccurate, and that baptism does not necessarily imply dipping. In ancient times, and in the lands where the apostles laboured, bathing was perhaps as frequently performed by affusion as immersion; [221:2] and it may be that the apostles varied their method of baptizing according to circumstances. [221:3] The ordinance was intended to convey the idea of washing or purifying; and it is obvious that water may be applied, in many ways, as the means of ablution. In the sacred volume sprinkling is often spoken of as equivalent to washing. [221:4]

As baptism was designed to supersede the Jewish circumcision, the Lord's Supper was intended to occupy the place of the Jewish Passover. [221:5] The Paschal lamb could be sacrificed nowhere except in the temple of Jerusalem, and the Passover was kept only once a year; but the Eucharist could be dispensed wherever a Christian congregation was collected; and at this period it seems to have been observed every first day of the week, at least by the more zealous and devout worshippers. [221:6] The wine, as well as the other element, was given to all who joined in its celebration; and the title of the "Breaking of Bread," [221:7] one of the names by which the ordinance was originally distinguished, supplies evidence that the doctrine of transubstantiation was then utterly unknown. The word Sacrament, as applied to Baptism and the Holy Supper, was not in use in the days of the apostles, and the subsequent introduction of this nomenclature, [222:1] probably contributed to throw an air of mystery around these institutions. The primitive disciples considered the elements employed in them simply as signs and seals of spiritual blessings; and they had no more idea of regarding the bread in the Eucharist as the real body of our Saviour, than they had of believing that the water of baptism is the very blood in which He washed His people from their sins. They knew that they enjoyed the light of His countenance in prayer, in meditation, and in the hearing of His Word; and that He was not otherwise present in these symbolic ordinances.

Whilst, in the Lord's Supper, believers hold fellowship with Christ, they also maintain and exhibit their communion with each other. "We, being many," says Paul, "are one bread and one body, for we are all partakers of that one bread." [222:2] Those who joined together in the observance of this holy institution were thereby pledged to mutual love; but every one who acted in such a way as to bring reproach upon the Christian name, was no longer admitted to the sacred table. Paul, doubtless, refers to exclusion from this ordinance, as well as from intimate civil intercourse, when he says to the Corinthians -- "I have written unto you not to keep company, if any man that is called a brother be a fornicator, or covetous, or an idolater, or a railer, or a drunkard, or an extortioner; with such an one no not to eat." [222:3]

In the synagogue all cases of discipline were decided by the bench of elders; [222:4] and it is plain, from the New Testament, that those who occupied a corresponding position in the Christian Church, also exercised similar authority. They are described as having the oversight of the flock, [222:5] as bearing rule, [223:1] as watching for souls, [223:2] and as taking care of the Church of God. [223:3] They are instructed how to deal with offenders, [223:4] and they are said to be entitled to obedience. [223:5] Such representations obviously imply that they were intrusted with the administration of ecclesiastical discipline.

This account of the functions of the spiritual rulers has been supposed by some to be inconsistent with several statements in the apostolic epistles. It has been alleged that, according to these letters, the administration of discipline was vested in the whole body of the people; and that originally the members of the Church, in their collective capacity, exercised the right of excommunication. The language of Paul, in reference to a case of scandal which had occurred among the Christians of Corinth, has been often quoted in proof of the democratic character of their ecclesiastical constitution. "It is reported commonly," says the apostle, "that there is fornication, among you, and such fornication as is not so much as named among the Gentiles, that one should have his father's wife..... Therefore put away from among yourselves that wicked person." [223:6] The admonition was obeyed, and the application of discipline seems to have produced a most salutary impression upon the mind of the offender. In his next letter the apostle accordingly alludes to this circumstance, and observes -- "Sufficient to such a man is this punishment, which was inflicted of many." [223:7] These words have been frequently adduced to shew that the government of the Corinthian Church was administered by the whole body of the communicants.

The various statements of Scripture, if rightly understood, must exactly harmonize, and a closer investigation of the case of this transgressor is all that is required to prove that he was not tried and condemned by a tribunal composed of the whole mass of the members of the Church of Corinth. His true history reveals facts of a very different character. For reasons which it would, perhaps, be now in vain to hope fully to explore, he seems to have been a favourite among his fellow-disciples; many of them, prior to their conversion, had been grossly licentious; and, it may be, that they continued to regard certain lusts of the flesh with an eye of comparative indulgence. [224:1] Some of them probably considered the conduct of this offender as only a legitimate exercise of his Christian liberty; and they appear to have manifested a strong inclination to shield him from ecclesiastical censure. Paul, therefore, felt it necessary to address them in the language of indignant expostulation. "Ye are puffed up," says he, "and have not rather mourned that he that hath done this deed might be taken away from among you.....Your glorying is not good. Know ye not that a little leaven leaveneth the whole lump." [224:2] At the same time, as an apostle bound to vindicate the reputation of the Church, and to enforce the rules of ecclesiastical discipline, he solemnly announces his determination to have the offender excommunicated. "I verily," says he, "as absent in body, but present in spirit, have judged already as though I were present, concerning him that hath so done this deed, in the name of our Lord Jesus Christ, when ye are gathered together, and my spirit, with the power of our Lord Jesus Christ, to deliver such an one unto Satan for the destruction of the flesh, that the spirit may be saved in the day of the Lord Jesus." [224:3] To deliver any one to Satan is to expel him from the Church, for whoever is not in the Church is in the world, and "the whole world lieth in the wicked one." [224:4] This discipline was designed to teach the fornicator to mortify his lusts, and it thus aimed at the promotion of his highest interests; or, as the apostle expresses it, he was to be excommunicated "for the destruction of the flesh, [225:1] that the spirit might be saved in the day of the Lord Jesus." It is obvious that the Church of Corinth was now in a state of great disorder. A partisan spirit had crept in amongst its members; [225:2] and it seems probable that those elders [225:3] who were anxious to maintain wholesome discipline were opposed and overborne. The fornicator had in some way contrived to make himself so popular that an attempt at his expulsion would, it was feared, throw the whole society into hopeless confusion. Under these circumstances Paul felt it necessary to interpose, to assert his apostolic authority, and to insist upon the maintenance of ecclesiastical order. Instead, however, of consulting the people as to the course to be pursued, he peremptorily delivers his judgment, and requires them to hold a solemn assembly that they may listen to the public announcement [225:4] of a sentence of excommunication. He, of course, expected that their rulers would concur with him in this decision, and that one of them would officially publish it when they were "gathered together."

When the case is thus stated, it is easy to understand why the apostle required all the disciples to "put away" from among themselves "that wicked person." Had they continued to cherish the spirit which they had recently displayed, they might either have encouraged the fornicator to refuse submission to the sentence, or they might have rendered it comparatively powerless. He therefore reminds them that they too should seek to promote the purity of ecclesiastical fellowship; and that they were bound to cooperate in carrying out a righteous discipline. They were to cease to recognize this fallen disciple as a servant of Christ; they were to withdraw themselves from his society; they were to decline to meet him on the same terms, as heretofore, in social intercourse; and they were not even to eat in his company. Thus would the reputation of the Church be vindicated; for in this way it would be immediately known to all who were without that he was no longer considered a member of the brotherhood.

The Corinthians were awakened to a sense of duty by this apostolic letter, and acted up to its instructions. The result was most satisfactory. When the offender, saw that he was cut off from the Church, and that its members avoided his society, he was completely humbled. The sentence of the apostle, or the eldership, if opposed or neglected by the people, might have produced little impression; but "the punishment which was inflicted of many" -- the immediate and entire abandonment of all connexion with him by the disciples at Corinth -- overwhelmed him with shame and terror. He felt as a man smitten by the judgment of God; he renounced his sin; and he exhibited the most unequivocal tokens of genuine contrition. In due time he was restored to Church fellowship; and the apostle then exhorted his brethren to readmit him to intercourse, and to treat him with kindness and confidence. "Ye ought," says he, "rather to forgive him and comfort him, lest perhaps such an one should be swallowed up with overmuch sorrow. Wherefore I beseech you that ye would confirm your love toward him." [227:1]

This case of the Corinthian fornicator has been recorded for the admonition and guidance of believers in all generations. It teaches that every member of a Christian Church is bound to use his best endeavours to promote a pure communion; and that he is not guiltless if, prompted by mistaken charity or considerations of selfishness, he is not prepared to co-operate in the exclusion of false brethren. Many an immoral minister has maintained his position, and has thus continued to bring discredit on the gospel, simply because those who had witnessed his misconduct were induced to suppress their testimony; and many a church court has been prevented from enforcing discipline by the clamours or intimidation of an ignorant and excited congregation. The command -- "Put away from among yourselves that wicked person," is addressed to the people, as well as to the ministry; and all Christ's disciples should feel that, in vindicating the honour of His name, they have a common interest, and share a common responsibility. Every one cannot be a member of a church court; but every one can aid in the preservation of church discipline. He may supply information, or give evidence, or encourage a healthy tone of public sentiment, or assist, by petition or remonstrance, in quickening the zeal of lukewarm judicatories. And discipline is never so influential as when it is known to be sustained by the approving verdict of a pious and intelligent community. The punishment "inflicted of many" -- the withdrawal of the confidence and countenance of a whole church -- is a most impressive admonition to a proud sinner.

In the apostolic age the sentence of excommunication had a very different significance from that which was attached to it at a subsequent period. Our Lord pointed out its import with equal precision and brevity when he said -- "If thy brother....neglect to hear the church, [228:1] let him be unto thee as an heathen man and a publican." [228:2] The Israelites could have no religious fellowship with heathens, or the worshippers of false gods; and they could have no personal respect for publicans, or Roman tax-gatherers, who were regarded as odious representatives of the oppressors of their country. To be "unto them as an heathen" was to be excluded from the privileges of their church; and to be "unto them as a publican" was to be shut out from their society in the way of domestic intercourse. When the apostle says -- "Now we command you, brethren, that ye withdraw yourselves from every brother that walketh disorderly and not after the ordinance [228:3] which he received of us," [228:4] he doubtless designed to intimate that those who were excommunicated should be admitted neither to the intimacy of private friendship nor to the sealing ordinances of the gospel. But it did not follow that the disciples were to treat such persons with insolence or inhumanity. They were not at liberty to act thus towards heathens and publicans; for they were to love even their enemies, and they were to imitate the example of their Father in heaven who "maketh his sun to rise on the evil and on the good, and sendeth rain on the just and on the unjust." [228:5] It is obvious from the address of the apostle to the Thessalonians that the members of the Church were not forbidden to speak to those who were separated from communion; and that they were not required to refuse them the ordinary charities of life. They were simply to avoid such an intercourse as implied a community of faith, of feeling, and of interest. "If any man," says he, "obey not our word by this epistle, note that man, and have no company with him, that he may be ashamed. Yet count him not as an enemy, but admonish him as a brother." [229:1]

How different was this discipline from that which was established, several centuries afterwards, in the Latin Church! The spirit and usages of paganism then supplanted the regulations of the New Testament, and the excommunication of Christianity was converted into the excommunication of Druidism. [229:2] Our Lord taught that "whoever would not hear the church" should be treated as a heathen man and a publican; but the time came when he who forfeited his status as a member of the Christian commonwealth was denounced as a monster or a fiend. Paul declared that the person excommunicated, instead of being counted as an enemy, should be admonished as a brother; but the Latin Church, in a long list of horrid imprecations, [229:3] invoked a curse upon every member of the body of the offender, and commanded every one to refuse to him the civility of the coldest salutation! The early Church acted as a faithful monitor, anxious to reclaim the sinner from the error of his ways: the Latin Church, like a tyrant, refuses to the transgressor even that which is his due, and seeks either to reduce him to slavery, or to drive him to despair.