And while they looked stedfastly toward heaven as he went up, behold, two men stood by them in white apparel;
And while they looked steadfastly toward heaven,.... For though he was taken out of their sight by the cloud, they kept looking upwards, and after him, if they could see him again, or any more of him:
as he went up; they looked up to heaven after him, as he went up from the earth, before the cloud took him out of their sight; and still they continued looking, as the cloud carried him up, until it was out of the reach of their sight, being willing to see the last of him in this way:
behold, two men stood by them in white apparel; that is, two angels in the form of men; it being usual with them to appear in human form: these on a sudden appeared and stood on the earth just by them; though the Ethiopic version renders it, "they stood above them", as if they were in the air over their heads; and they appeared in white apparel, as the angel at the sepulchre in
Matthew 28:2 which was a symbol both of their purity and holiness, and of their lustre and glory. The Ethiopic version renders it, "they were clothed with lightning"; they appeared in such a dazzling form, that it looked as if they were covered with lightning; as the angel that appeared at Christ's resurrection, his countenance is said to be as lightning; which must at once fix the attention of the disciples to them, and strike them with surprise: hence a "behold" is prefixed to this: and hereby they knew that they were not common and ordinary men, or mere men, but angels in such a form.