John 7:16

How then did the Lord answer those that were marvelling how He knew letters which He had not learned? "My doctrine," saith He, "is not mine, but His that sent me." This is the first profundity. For He seems as if in a few words He had spoken contraries. For He says not, This doctrine is not mine; but, "My doctrine is not mine." If not Thine, how Thine? If Thine, how not Thine? For Thou sayest both: both, "my doctrine;" and, "not mine." For if He had said, This doctrine is not mine, there would have been no question. But now, brethren, in the first place, consider well the question, and so in due order expect the solution. For he who sees not the question proposed, how can he understand what is expounded? The subject of inquiry, then, is that which He says, "My, not mine" this appears to be contrary; how "my," how "not mine"? If we carefully look at what the holy evangelist himself says in the beginning of his Gospel, "In the beginning was the Word, and the Word was with God, and the Word was God;" thence hangs the solution of this question. What then is the doctrine of the Father, but the Father's Word? Therefore, Christ Himself is the doctrine of the Father, if He is the Word of the Father. But since the Word cannot be of none, but of some one, He said both "His doctrine," namely, Himself, and also, "not His own," because He is the Word of the Father. For what is so much "Thine" as Thyself? And what so much not Thine as Thyself, if that Thou art is of another? The Word then is God; and it is also the Word of a stable, unchangeable doctrine, not such as can be sounded by syllables and fleeting, but abiding with the Father, to which abiding doctrine let us be converted, being admonished by the transitory sounds of the voice. For that which is transitory does not so admonish us as to call us to transitory things. We are admonished to love God. […]

(Tract. xxix. s. 3) Mine is not mine, appears a contradiction; why did He not say, This doctrine is not Mine? Because the doctrine of the Father being the Word of the Father, and Christ Himself being that Word, Christ Himself is the doctrine of the Father. And therefore He calls the doctrine both His own, and the Father's. A word must be a word of some one's. What is so much Thine as Thou, and what is so much not Thine as Thou, if what Thou art, Thou art of another. His saying then, My doctrine is not Mine own, seems briefly to express the truth, that He is not from Himself; it refutes the Sabellian heresy, which dares to assert that the Son is the same as the Father, there being only two names for one thing. (de Trin. i. c. xi) Or thus: In one sense He calls it His, in another sense not His; according to the form of the Godhead His, according to the form of the servant not His. (Tract. xxix. s. 6) Should any one however not understand this, let him hear the advice which immediately follows from our Lord: If any man will do His will, he shall know of the doctrine, whether it be of God, or whether I speak of Myself. What meaneth this, If any man will do His will? To do His will is to believe on Him, as He Himself says, This is the work of God, that ye believe on Him whom He hath sent. (c. 6:29) And who does not know, that to work the work of God, is to do His will? To know is to understand. Do not then seek to understand in order to believe, but believe in order to understand, for, Except ye believe, ye shall not understand. (Is. 7:9. Vulg.)

We shall find that indeed true that is written by one of the wise men, The Spirit of the Lord hath filled the world, and the ear of hearing heareth all things. But to those who of utter folly, yea rather of blasphemy, suppose that ought they utter will escape the Divine Mind, the Godlike Psalmist says, Understand, ye brutish among the people, and ye fools, when will ye be wise? He that planted the ear, heareth He not? for how could it possibly happen that He should not surely hear all things, who implanteth the sense of hearing into them that were made by Him? See therefore in this too again that the Lord is by Nature God. For the secret whispers of the Jews in the crowd He is not ignorant of; He receives them into His Ears in God-befitting way, albeit from fear of the rulers they say nothing openly concerning Him. And when on one occasion certain of those who had rushed together into the temple, marvelled and were reasoning (as is like) or gently saying one to another, How knoweth This Man letters not having learned? needs does He again show Himself Equal to God the Father Who learneth nothing at all, but hath the knowledge of all things by Nature and without learning, because He surpasseth all understanding and soareth above all wisdom that is in things that are. […]

"My doctrine is not Mine." Again He answereth to their secret thoughts, referring them to the Father, and so desiring to stop their mouths.

But how is the doctrine His and not His? For He said not, "This doctrine is not Mine"; but having first said, "it is Mine," and having claimed it as His own, He then added, "it is not Mine." How then can the same thing be both "His" and not "His"? It is "His," because He spake it not as one who had been taught; and it is "not His," because it was the doctrine of the Father. How then saith He, "All that is the Father's is Mine, and Mine His"? (c. xvii. 10.) "For if because the doctrine is the Father's, it is not thine, that other assertion is false, for according to that it ought to be thine." But the "is not Mine," affords a strong proof that His doctrine and the Father's are one; as if He had said, "It hath nothing different, as though it were another's. For though My Person be different, yet so do I speak and do as not to be supposed to speak or do anything contrary to the Father, but rather the very same things that the Father saith and doeth."