7 But now He condescends to us, and He who a little before was speaking as God, now begins to speak as man. Notwithstanding, the same is man who is God, for God was made man; but was made what He was not, without losing what He was. The man therefore was added to the God, that He might be man who was God, but not that He should now henceforth be man and not be God. Let us then hear Him also as our brother whom we did hear as our Maker. Our Maker, because the Word in the beginning; our Brother, because born of the Virgin Mary: Maker, before Abraham, before Adam, before earth, before heaven, before all things corporeal and spiritual; but Brother, of the seed of Abraham, of the tribe of Judah, of the Israelitish virgin.
If therefore we know Him who speaks to us as both God and man, let us understand the words of God and of man; for sometimes He speaks to us such things as are applicable to the majesty, sometimes such as are applicable to the humility. For the selfsame is high who was made low, that He might make us high who are low. What, then, says He? “The Father will show” to me “greater than these, that you may marvel.” To us, therefore, He is about to show, not to Him. And since it is to us that the Father is to show, for that reason He said, “that you may marvel.”
He has, in fact, explained what He meant in saying, “The Father will show” to me. Why did He not say, The Father will show to you; but, He will show to the Son? Because also we are members of the Son; and like as what we the members learn, He Himself in a manner learns in His members. How does He learn in us? As He suffers in us. Whence may we prove that He suffers in us? From that voice out of heaven, “Saul, Saul, why do you persecute me?” Is it not Himself that will sit as Judge in the end of the world, and, setting the just on the right, and the wicked on the left, will say, “Come, you blessed of my Father, receive the kingdom; for I was hungry, and you gave me to eat”?
And when they shall answer, “Lord, when saw we You hungry?” He will say to them, “Since ye gave to one of the least of mine, you gave to me.” Let us at this time question Him, and let us say to Him, Lord, when will You be a learner, seeing Thou teachest all things? Immediately, indeed, He makes answer to us in our faith, When one of the least of mine does learn, I learn.
Source: Tractates on the Gospel of John (New Advent)