7 “He that comes from heaven is above all; and what He has seen and heard, that He testifies: and no man receives His testimony.” Comes from heaven, is above all, our Lord Jesus Christ; of whom it was said above, “No man has ascended into heaven, but He that came down from heaven, the Son of man who is in heaven.” And He is above all; “and what He has seen and heard, that He speaks.” Moreover, He has a Father, being Himself the Son of God; He has a Father, and He also hears of the Father.
And what is that which He hears of the Father? Who can unfold this? When can my tongue, when can my heart be sufficient, either the heart to understand, or the tongue to utter, what that is which the Son has heard from the Father? May it be the Son has heard the Word of the Father? Nay, the Son is the Word of the Father. You see how all human effort is here wearied out; you see how all guessing of our heart, all straining of our darkened mind, here fails. I hear the Scripture saying that the Son speaks that which He hears from the Father; and again, I hear the Scripture saying that the Son is Himself the Word of the Father: “In the beginning was the Word, and the Word was with God, and the Word was God.”
The words that we speak are fleeting and transient: as soon as your word has sounded from your mouth, it passes away; it makes its noise, and passes away into silence. Can you follow your sound, and hold it to make it stand? Your thought, however, remains, and of that thought that remains you utter many words that pass away. What say we, brethren? When God spoke, did He give out a voice, or sounds, or syllables? If He did, in what tongue spoke He? In Hebrew, or in Greek, or in Latin?
Tongues are necessary where there is a distinction of nations. But there none can say that God spoke in this tongue, or in that. Observe your own heart. When you conceive a word which you may utter—For I will say, if I can, what we may note in ourselves, not whereby we may comprehend that—well, when you conceive a word to utter, you mean to utter a thing, and the very conception of the thing is already a word in your heart: it has not yet come forth, but it is already born in the heart, and is waiting to come forth.
But you consider the person to whom it is to come forth, with whom you are to speak: if he is a Latin, you seek a Latin expression; if a Greek, you think of Greek words; if a Punic, you consider whether you know the Punic language: for the diversity of hearers you have recourse to various tongues to utter the word conceived; but the conception itself was bound by no tongue in particular. Whilst therefore God, when speaking, required not a language, nor took up any kind of speech, how was He heard by the Son, seeing that God's speaking is the Son Himself?
As, in fact, you have in your heart the word that you speak, and as it is with you, and is none other than the spiritual conception itself (for just as your soul is spirit, so also the word which you have conceived is spirit; for it has not yet received sound to be divided by syllables, but remains in the conception of your heart, and in the mirror of the mind); so God gave out His Word, that is, begot the Son. And you, indeed, begettest the word even in your heart according to time; God without time begot the Son by whom He created all times.
Whilst, therefore, the Son is the Word of God, and the Son spoke to us not His own word, but the word of the Father, He willed to speak Himself to us when He was speaking the word of the Father. This it is that John said, as was fit and necessary; and we have expounded according to our ability. He whose heart has not yet attained to a proper perception of so great a matter, has whither to turn himself, has where to knock, has from whom to ask, from whom to seek, of whom to receive.
Source: Tractates on the Gospel of John (New Advent)