John 16:29

The inward state of Christ's disciples, when before His passion He talked with them as with children of great things, but in such a way as befitted the great things to be spoken to children, because, having not yet received the Holy Spirit, as they did after His resurrection, either by His own breathing upon them, or by descent from above, they had a mental capacity for the human rather than the divine, is everywhere declared through the Gospel by numerous testimonies; and of a piece therewith, is what they said in the lesson before us. For, says the evangelist, "His disciples say unto Him: Lo, now speakest Thou plainly, and utterest no proverb. Now we are sure that Thou knowest all things, and needest not that any man should ask Thee: by this we believe that Thou camest forth from God." The Lord Himself had said shortly before, "These things have I spoken unto you in proverbs: the hour cometh, when I shall no more speak to you in proverbs." How, then, say they, "Lo, now speakest Thou plainly, and utterest no proverb"? Was the hour, indeed, already come, when He had promised that He would no more speak unto them in proverbs? Certainly that such an hour had not yet come, and when thus that hour is still the subject of promise when He was to speak without proverbs, why say they, "Lo, now speakest Thou plainly, and utterest no proverb;" but just because those things, which He knows to be proverbs to those who have no understanding, they are still so far from understanding, that they do not even understand that they do not understand them? For they were babes, and had as yet no spiritual discernment of what they heard regarding things that had to do not with the body, but with the spirit.

(Tr. ciii) But why do they say so, when the hour in which He was to speak without proverbs was yet future, and only promised? Because, our Lord's communications still continuing proverbs to them, they are so far from understanding them, that they do not even understand their not understanding them.

For God is not born from God by the ordinary process of a human childbirth; this is no case of one being issuing from another by the exertion of natural forces. That birth is pure and perfect and stainless; indeed, we must call it rather a proceeding forth than a birth. For it is One from One; no partition, or withdrawing, or lessening, or efflux, or extension, or suffering of change, but the birth of living nature from living nature. It is God going forth from God, not a creature picked out to bear the name of God. His existence did not take its beginning out of nothing, but went forth from the Eternal; and this going forth is rightly entitled a birth, though it would be false to call it a beginning.

By this the holy Apostles did not understand that He had gone forth, in the sense of having been sent, from God. For they had often heard Him confess, in His earlier discourses, that He was sent; but what they hear now is the express statement that He had gone forth from God. This opens their eyes to perceive from His works His Divine nature. The fact that He had gone forth from God makes clear to them His true Divinity, and so they say, Now therefore we are sure that Thou knowest all things, and needest not that any man should ask Thee; by this we believe that Thou wentest forth from God. The reason why they believe that He went forth from God is that He both can, and does, perform the works of God. Their perfect assurance of His Divine nature is the result of their knowledge, not that He is come from God, but that He did go forth from God.

(Hom. lxxix) The disciples were so refreshed with the thought of being in favour with the Father, that they say they are sure He knows all things: His disciples said unto Him, Now speakest Thou plainly, and speakest no proverb.