Who also said, You men of Galilee, why stand you gazing up into heaven? this same Jesus, who is taken up from you into heaven, shall so come in like manner as you have seen him go into heaven.
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Bede
AD 735
The angels appeared to them for two reasons, namely to console them in their sorrow at His ascension by reminding them of His return, and to show that He had truly gone to Heaven, not merely apparently so, as in the case of Elijah (2Kings 2:11).