New Revised Standard Version
When he had said this, as they were watching, he was lifted up, and a cloud took him out of their sight.

Contemporary English Version
After Jesus had said this and while they were watching, he was taken up into a cloud. They could not see him,

New American Bible
When he had said this, as they were looking on, he was lifted up, and a cloud took him from their sight.

Douay-Rheims Bible
And when he had said these things, while they looked on, he was raised up: and a cloud received him out of their sight.

And when he had said these things, while they looked on, he was raised up: and a cloud received him out of their sight.

when.

Acts 1:2 Until the day on which, giving commandments by the Holy Ghost to the apostles whom he had chosen, he was taken up.

Psalm 68:18 Thou hast ascended on high, thou hast led captivity captive; thou hast received gifts in men. Yea for those also that do not believe, the dwelling of the Lord God.

Mark 16:19 And the Lord Jesus, after he had spoken to them, was taken up into heaven and sitteth on the right hand of God.

Luke 24:50,51 And he led them out as far as Bethania: and lifting up his hands, he blessed them. . . .

John 6:62 If then you shall see the Son of man ascend up where he was before?

Ephesians 4:8-12 Wherefore he saith: Ascending on high, he led captivity captive: he gave gifts to men. . . .

a cloud.

Exodus 19:9 The Lord said to him: Lo, now will I come to thee in the darkness of a cloud, that the people may hear me speaking to thee, and may believe thee for ever. And Moses told the words of the people to the Lord.

Exodus 34:5 And when the Lord was come down in a cloud, Moses stood with him, calling upon the name of the Lord.

Isaiah 19:1 The burden of Egypt. Behold the Lord will ascend upon a swift cloud, and will enter into Egypt, and the idols of Egypt shall be moved at his presence, and the heart of Egypt shall melt in the midst thereof.

Daniel 7:13 I beheld, therefore, in the vision of the night, and lo, one like the Son of man came with the clouds of heaven, and he came even to the ancient of days: and they presented him before him.

Luke 21:27 And then they shall see the Son of man coming in a cloud, with great power and majesty.

Revelation 1:7 Behold, he cometh with the clouds, and every eye shall see him: and they also that pierced him. And all the tribes of the earth shall bewail themselves because of him. Even so. Amen.

Revelation 11:12 And they heard a great voice from heaven, saying to them: Come up hither. And they went up to heaven in a cloud: and their enemies saw them.

Revelation 14:4 These are they who were not defiled with women: for they are virgins. These follow the Lamb whithersoever he goeth. These were purchased from among men, the firstfruits to God and to the Lamb.