John 16:30

(Hom. lxxix. 2) But since His answer met what was in their minds, they add, Now we are sure that Thou knowest all things. See how imperfect they yet were, after so many and great things now at last to say, Now we are sure &c. saying it too as if they were conferring a favour. And needest not that any man should ask thee; i. e. Thou knowest what offends us, before we tell Thee, and Thou hast relieved us by saying that the Father loveth us.

(Tr. ciii. 2) Why this remark? To one Who knew all things, instead of saying, Thou needest not that any man should ask Thee; it would have been more appropriate to have said, Thou needest not to ask any man: yet we know that both of these were done, viz. that our Lord both asked questions, and was asked. But this is soon explained; for both were for the benefit, not of Himself, but of those whom He asked questions of, or by whom He was asked. He asked questions of men not in order to learn Himself, but to teach them: and in the case of those who asked questions of Him, such questions were necessary to them in order to gain the knowledge they wanted; but they were not necessary to Him to tell Him what that was, because He knew the wish of the enquirer, before the question was put. Thus to know men's thoughts beforehand was no great thing for the Lord, but to the minds of babes it was a great thing: By this we know that Thou camest, forth from God.

(vi. de Trin. c. 34) They believe that He came forth from God, because He does the works of God. For whereas our Lord had said both, I came forth from the Father, and, I am come into the world from the Father, they testified no wonder at the latter words, I am come into the world, which they had often heard before. But their reply shows a belief in and appreciation of the former, I came forth from the Father. And they notice this in their reply: By this we believe that Thou camest forth from God; not adding, and art come into the world, for they knew already that He was sent from God, but had not yet received the doctrine of His eternal generation. That unutterable doctrine they now began to see for the first time in consequence of these words, and therefore reply that He spoke no longer in parables. For God is not born from God after the manner of human birth: His is a coming forth from, rather than a birth from, God. He is one from one; not a portion, not a defection, not a diminution, not a derivation, not a pretension, not a passion, but the birth of living nature from living nature. He is God coming forth from God, not a creature appointed to the name of God; He did not begin to be from nothing, but came forth from an abiding (manente) nature. To come forth, hath the signification of birth, not of beginning.