John 17:11
“And now I am no more in the world, but these are in the world.”
That is, “Although I appear no longer in the flesh, yet by these am I glorified.” But why does He say continuously, that, “I am not in the world”; and that, “because I leave them I commit them to You”; and that, “when I was in the world I kept them”? For if one should take these words in their simple sense, many absurdities will follow. For how could it be reasonable to say, that He is no longer in the world, and that when He departs He commits them to another? Since these are the words of a mere man parting from them forever. Do you see how He speaks for the most part like a man, and in a way adapted to their state of mind, because they thought that they had a greater degree of safety from His presence? Wherefore He says, “While I was with them, I kept them.” Yet He tells them, “I come to you”; and, “I am with you till the end.” How then says He these words, as if about to be parted from them? He addresses Himself, as I said before, to their thoughts, that they may take breath a little when they hear Him speaking thus, and delivering them over to the care of the Father. For since, after hearing many exhortations from Him, they were not persuaded, He then holds converse with the Father, manifesting His affection for them. As though He had said, “Since You call Me to Yourself, place these in safety; for I come to You.” “What sayest Thou? Are You not able to keep them?” “Yea, I am able.” “Wherefore then do You speak thus?” “That they may have My joy fulfilled”; that is, “may not be confounded, as being imperfect.” And by these words He showed that He had spoken all these things so, to give them rest and joy. For the saying appears to be contradictory. “Now I am no longer in the world, and these are in the world.” This was what they were suspecting. For a while therefore He condescends to them, because had He said, “I keep them,” they would not have so well believed; wherefore He says, “Holy Father, keep them through Your own Name”; that is, “by your help.”
Source: Homilies on the Gospel of John (New Advent)