But just as when we see a child crying, and pertinaciously wishing to get something from us that is not expedient for him, we hide the thing, and show him our empty hands, and say, “See, we have it not:” the like has Christ here done with the Apostles. But as the child, even when we show him [our empty hands], persists with his crying, conscious he has been deceived, and then we leave him, and depart, saying, “Such an one calls me:” and we give him something else instead, in order to divert him from his desire, telling him it is a much finer thing than the other, and then hasten away; in like manner Christ acted. The disciples asked to have something, and He said He had it not. And on the first occasion he frightened them. Then again they asked to have it now: He said He had it not; and He did not frighten them now, but after having shown [the empty hands], He has done this, and gives them a plausible reason: “Which the Father,” He says, “has put in his own power.” What? Thou not know the things of the Father! You know Him, and not what belongs to Him! And yet You have said, “None knows the Father but the Son”; and, “The Spirit searches all things, yea, the deep things of God”; and Thou not know this! But they feared to ask Him again, lest they should hear Him say, “Are ye also without understanding?” For they feared Him now much more than before. “But you shall receive power, after that the Holy Ghost has come upon you.” As in the former instance He had not answered their question (for it is the part of a teacher to teach not what the disciple chooses, but what is expedient for him to learn), so in this, He tells them beforehand, for this reason, what they ought to know, that they may not be troubled. In truth, they were yet weak. But to inspire them with confidence, He raised up their souls, and concealed what was grievous. Since he was about to leave them very shortly, therefore in this discourse He says nothing painful. But how? He extols as great the things which would be painful: all but saying, “'Fear not': for you shall receive power, after that the Holy Ghost has come upon you; and you shall be witnesses unto Me both in Jerusalem, and in all Judea, and in Samaria.” For since he had said, “Go not into the way of the Gentiles, and into any city of the Samaritans enter ye not”, what there He left unsaid, He here adds, “And to the uttermost part of the earth;” and having spoken this, which was more fearful than all the rest, then that they may not again question Him, He held His peace. “And having this said, while they beheld, He was taken up; and a cloud received Him out of their sight”. Do you see that they did preach and fulfil the Gospel? For great was the gift He had bestowed on them. In the very place, He says, where you are afraid, that is, in Jerusalem, there preach ye first, and afterwards unto the uttermost part of the earth. Then for assurance of what He had said, “While they beheld, He was taken up.” Not “while they beheld” did He rise from the dead, but “while they beheld, He was taken up.” Inasmuch, however, as the sight of their eyes even here was not all-sufficient; for in the Resurrection they saw the end, but not the beginning, and in the Ascension they saw the beginning, but not the end: because in the former it had been superfluous to have seen the beginning, the Lord Himself Who spoke these things being present, and the sepulchre showing clearly that He is not there; but in the latter, they needed to be informed of the sequel by word of others: inasmuch then as their eyes do not suffice to show them the height above, nor to inform them whether He is actually gone up into heaven, or only seemingly into heaven, see then what follows. That it was Jesus Himself they knew from the fact that He had been conversing with them (for had they seen only from a distance, they could not have recognized Him by sight), but that He is taken up into Heaven the Angels themselves inform them. Observe how it is ordered, that not all is done by the Spirit, but the eyes also do their part. But why did “a cloud receive Him?” This too was a sure sign that He went up to Heaven. Not fire, as in the case of Elijah, nor fiery chariot, but “a cloud received Him;” which was a symbol of Heaven, as the Prophet says; “Who makes the clouds His chariot”; it is of the Father Himself that this is said. Therefore he says, “on a cloud;” in the symbol, he would say, of the Divine power, for no other Power is seen to appear on a cloud. For hear again what another Prophet says: “The Lord sits upon a light cloud”. For it was while they were listening with great attention to what He was saying, and this in answer to a very interesting question, and with their minds fully aroused and quite awake, that this thing took place. Also on the mount [Sinai] the cloud was because of Him: since Moses also entered into the darkness, but the cloud there was not because of Moses. And He did not merely say, “I go,” lest they should again grieve, but He said, “I send the Spirit”; and that He was going away into heaven they saw with their eyes. O what a sight they were granted! “And while they looked steadfastly,” it is said, “toward heaven, as he went up, behold, two men stood by them in white apparel; which also said, You men of Galilee, why stand ye gazing up into heaven? This same Jesus, which is taken up from you into heaven”— they used the expression “This” demonstratively, saying, “this Jesus, which is taken up from you into heaven, shall thus”— demonstratively, “in this way”— “come in like manner as you have seen Him going into heaven.” (<!--<span class="stiki"></span>-->v. 10-11.) Again, the outward appearance is cheering [“in white apparel”]. They were Angels, in the form of men. And they say, “You men of Galilee:” they showed themselves to be trusted by the disciples, by saying, “You men of Galilee.” For this was the meaning: else, what needed they to be told of their country, who knew it well enough? By their appearance also they attracted their regard, and showed that they were from heaven. But wherefore does not Christ Himself tell them these things, instead of the Angels? He had beforehand told them all things; [“What if you shall see the Son of Man] going up where He was before?”.
Moreover the Angels did not say, 'whom you have seen taken up,' but, “going into heaven:” ascension is the word, not assumption; the expression “taken up,” belongs to the flesh. For the same reason they say, “He which is taken up from you shall thus come,” not, “shall be sent,” but, “shall come. He that ascended, the same is he also that descended”. So again the expression, “a cloud received Him:” for He Himself mounted upon the cloud. Of the expressions, some are adapted to the conceptions of the disciples, some agreeable with the Divine Majesty. Now, as they behold, their conceptions are elevated: He has given them no slight hint of the nature of His second coming. For this, “Shall thus come,” means, with the body; which thing they desired to hear; and, that he shall come again to judgment “thus” upon a cloud. “And, behold, two men stood by them.” Why is it said, “men?” Because they had fashioned themselves completely as such, that the beholders might not be overpowered. “Which also said:” their words moreover were calculated for soothing: “Why stand ye gazing up into heaven?” They would not let them any longer wait there for Him. Here again, these tell what is greater, and leave the less unsaid. That “He will thus come,” they say, and that “ye must look for Him from heaven.” For the rest, they called them off from that spectacle to their saying, that they might not, because they could not see Him, imagine that He was not ascended, but even while they are conversing, would be present ere they were aware. For if they said on a former occasion, “Where are You going?” much more would they have said it now.
Source: Homilies on Acts (New Advent)