There are expressions in this psalm which sound harsh and cruel, and which Christians would shrink from using. But, on the other hand, there is much here that comes home to our experience, and that is helpful and comforting in the great trials of life. It is something to know that good men have suffered affliction before us - that they have been falsely accused and foully wronged, that they have felt the pangs of grief and the bitterness of disappointment, and that they have had to bear much and wait long before deliverance came. The lesson is clear. It is - Wait upon God. This is the refrain, which comes so sweetly at the middle (ver. 10), and then with increased force and emphasis at the end (ver. 17). The figure seems that of a sentinel on his tower. He is set there to watch. He must be vigilant and patient. There is much to try him, but not till morning breaks will he find release.

I. WAITING UPON GOD ASSURES DELIVERANCE. Waiting implies faith and hope. "The husbandman waiteth for the harvest." The physician waits for the effect of his remedies. The father waits for the time when his son is educated, and fit to take his place in the world. So we are to have faith, to hold ourselves still, in patient expectancy, till God's will is made known. Waiting does not preclude personal effort. On the contrary, it implies it. God will not do for us what he has made us able to de for ourselves. Our duty is to work, and wait upon God for his blessing. We must do our part, if we expect God to do his part. But there are times when we have, so far as we know, done all in our power, when we have exhausted all lawful efforts, and yet our condition is not bettered, but rather grown worse. Our straits are great. Our needs are urgent. Our enemies press us on every side, and shout as if sure of their prey. What comfort it is, at such a time, to commit ourselves to God, and to wait patiently for him from whom our salvation cometh! Remember what God is, and what he has done. He is our "Strength" and our "Defence." God in us is our Strength - our strength made perfect in weakness. We in God is our "Defence" - our Strong Tower to which we run and are safe.

II. WAITING UPON GOD AWAKENS PRAISE. (Vers. 14 17.) Here is a sweet strain of thanksgiving. The rage and malice of the enemy still continue, but it is malice that is defeated, and rage that is baulked of its prey. The "morning" brings deliverance, and, instead of the shrieks of the victim, there are the songs of the victor. God has saved his servant who trusted in him. How often has the same thing come true! God's people, waiting upon him in the day of their trouble, have found "defence" and "refuge." God's power has delivered them from their enemies; God's "mercy" has brought joy and peace to their hearts. Therefore they, with renewed ardour, say, "Unto thee, O my Strength, will I sing: for God is my Defence, and the God of my mercy." - W.F.

Our trials and troubles, while they test and develop us, do also by Divine grace strengthen and improve us, and ever have we great cause to bless God for them when grace sanctifies them to our highest good. Had not David been a man of many afflictions he would never have penned such a verse as our text, a confident utterance of unstaggering faith, full of meaning, rich with consolation, the very cream of assured hope in God.

I. DAVID'S LOOKING TO HIS GOD. "The God of mercy," saith he. Note that this psalm was composed by him upon the occasion of his being shut up in the house of Michal, Saul's daughter, and surrounded by his adversaries. The messengers of the bloodthirsty king watched the house all night long, to kill him, and when they had not effected their purpose, Saul demanded that he should be brought, on his bed, into his presence, that he might slay him. It was not easy for a man, when his enemies were watching the house, to escape out of their hands. David, however, does not appear to have been at all disturbed, but with perfect confidence in God he expected that a way of escape would be made for him.

1. David looked to God on this occasion because he had before this habitually waited upon Him. His faith had realized the existence of God, and his soul had felt the power of that realized truth. This is a thing unknown to the unconverted, and unfelt to any high degree by large numbers of those who profess to know the Lord.

2. David was driven more closely to his God by the peculiar trouble with which he was environed. It is a blessed thing when the waves of affliction wash us upon the rock of confidence in God alone, when darkness below gives us an eye to the light above. The psalmist says in the verse preceding the text, "Because of his strength" — that is, the strength of the foe — "will I wait upon Thee, for God is my defence." Because the enemy is too strong for me, therefore will I turn to my God, and invoke His omnipotence as my defence. To come to the end of yourself is to get to the beginning of your God. Blessed is that extremity which is God's opportunity.

3. As soon as David had looked alone to his God his trials grew small. In his own esteem they grew to be nothing, for he says, "Thou, O Lord, shalt laugh at them, Thou shalt have all the heathen in derision"; and methinks something of the laughter of God penetrated David's spirit; and in that house wherein he was enclosed as a prisoner he smiled in his heart at the disappointment which awaited his foes. Faith laughs at that which fear weeps over; it leaps over mountains at whose feet mere mortal strength lies down to die.

II. DAVID'S APPROPRIATION OF THE DIVINE MERCY. "The God of my mercy." Notice that the pith of the title lies in the appropriating word "my." Luther used to say that the very soul of divinity lay in the possessive pronouns; another divine said that all the stir there ever has been in the world has been caused by meum and tuum, mine and thine. "It is mine," says one man; "It is mine," cries another man, and then comes a conflict. "It is mine," says one king; "Nay," says another, "it is not thine," and then fierce war begins. Nothing influences a man so much as that which he calls his own. "The God of my mercy."

1. David appropriated to himself a portion of Divine mercy as being peculiarly his; and we shall never advance in the divine life unless we do the same, for the mercy which is in common to all men, of what avail is it to any man? But the mercy which any one man by faith grasps for himself, this is the mercy which will bless him and which he will prize above all things.

2. I think he meant, too, that there was a portion of mercy which he had already received, which was, therefore, altogether his own. The "God of my mercy" — he meant the God of the mercy he had already experienced. Well may it bring the tears into your eyes to think of it. The mercy which nursed you in your infancy; the mercy which watched over you in your youth and kept you when you were apt to stray; the mercy which restrained you from many a deadly sin, etc.

3. And, remember, that all the mercy you have had is little compared with the mercy you have yet to receive. As the rich father thinks, "This will I give to my eldest son, and that to the second, and that to the third," and so he puts by a portion for each of his children; so has God mapped out and allotted for each one of us some choice and special mercy fitted for our peculiar case, which no one can receive but ourselves, but which we must and shall obtain.

4. But I think David made a larger grasp than this, for when he said, "The God of my mercy," he felt as if all the mercy in the heart of God belonged to him. If any one saint should have all the wants of all the saints in the world put upon him, and if his necessities should be so great that nothing would supply them but the whole of the infinite mercy which fills the heart of God, that child of God should have all the mercy which the Lord Himself can dispense.

III. David CONFINING IN GOD. "The God of my mercy shall prevent me," or anticipate me by His mercy. Now, it so happens that the Hebrew word may be read in all three tenses, and some have said it should be understood, "The God of my mercy has prevented me"; others, "does prevent me"; and a third party, like our translators, read it, "shall prevent me." Whichever tense you choose is true, and the whole three put together may be viewed as the full meaning of the passage.

1. "The Lord has prevented me." This is one of the grand doctrines of the Gospel, the doctrine of eternal love, spontaneous, self-generated, having no cause but itself. God loved us before we loved Him — he prevented us with love. Before His people were born God had elected and redeemed them, and prepared the Gospel, by which in due time they are called. He is before us in all good things. O Lord, Thou hast the first hand with Thy people; they seek Thee early, but Thou art up before them, Thou hast distanced them in the race of affection; Alpha art Thou, indeed!

2. The Lord hast prevented us, but the meaning of the passage is that He does still prevent us. Is He not daily doing so? Before you can feel the pinch of want the mercy is given. God goes before you day by day, and His paths drop fatness. Even in the common acceptation of the word "prevent" God has often so gone before us that He has prevented us from the commission of many sins, into which otherwise we should have fallen to our sorrow and damage. Again, how often has He prevented our prayers! Before we have asked, we have had; while we were yet calling, we have received. The desire of the righteous is granted oftentimes as soon as it takes shape, and before it is expressed.

3. It will always be so. God will prevent us. A good captain, when he is marching an army through a country, takes care to make provision for every emergency. It is time for the soldier, to camp, and they need tents. Bring up the baggage wagons, here are the tents which you ask for! The men must have their rations. Here they are! Serve them out! The meat needs cooking. See, there are the portable kitchens and the fuel! The army comes to a river by and by, how will they pass it? Why, the engineers are ready, and pontoons are very soon thrown across. It is wonderful how the well-skilled commander foresees every possible emergency, and has everything ready just at the nick of time. Much more is it so with our God. So let us close with these three practical reflections. If He prevents us with mercy, let us not hesitate to come to Him. Loiter not, O soul, if thou wouldst have the mercy of God. Is God so quick? Wilt thou be slow? Does He go first, and wilt thou not follow?

4. Is God so quick in mercy? Let us who are His be very quick in service. Say in your heart, "My God, since Thou dost prevent me, I cannot hope to keep pace with Thy mercy, but at any rate I will not lag further behind Thee than I must. When I have done all I can for Thee, how little it is, but that little shall be done." George Herbert once described the good man as resolved "to build a spital, or mend common ways," and in his day these were acts of charity which piety delighted in; other good deeds are more fitting for these days. Houses for worship are wanted in many a populous district, and orphan children need to be fed. He who can buy no sweet cane with money, can bring time and zeal and effort, and these are precious. What, then, will you do?

5. And now finally, believer, cast yourself into your Lord's arms. Have done with fretting; have done with anxiety and doubt. Mount like the lark to your God, and sing as you mount.

( C. H. Spurgeon.)