John Chrysostom

"If," saith one of them, "we shall see Thee, whither goest Thou? And if Thou goest, how shall we see Thee?" Therefore they say, "We cannot tell what He saith." That He was about to depart, they knew; but they knew not that He would shortly come to them. On which account He rebuketh them, because they did not understand His saying.

Homily on the Gospel of John 79 ↗

Theophylact of Ohrid

Therefore one might well wonder how they did not understand His words. Most likely, the grief that had taken hold of their soul was erasing from their memory what was being said, or a lack of comprehension came upon them due to the obscurity of the words themselves. And so a certain contradiction appeared to them in the words of Jesus: "If we shall see You, then where are You going? But if You are going away, then how shall we see You?" This seemed to them a riddle.

Commentary on John ↗

Thomas Aquinas

2121 Now we see the perplexity of the disciples: first, they talk it over among themselves; secondly, we see the reason for their perplexity; and thirdly, we see their point of view and attitude. 2122 The disciples questioned one another about the Lord's statement, saying, What does he mean by a little while? They show an admirable respect for Christ for it was so great that they did not presume to question him. The angels do the same: "Who is this that comes from Edom, in crimsoned garments from Bozrah" (Is 63:1). …

Commentary on John ↗

Bonaventure

Some of his disciples therefore said, etc. Here the second point is touched upon, namely the doubt of the disciples, which proceeded from what he had said: in a little while not to be seen and to be seen; on account of which he says: Some of his disciples therefore said to one another: What is this that he says to us: A little while, and you shall not see me; and again a little while, and you shall see me? …

Commentary on John, Chapter 16 ↗