Augustine of Hippo

(Tr. xl. s. 3. et seq.) Or thus: Having said, Then shall ye know that I am, and in this, I am, implied the whole Trinity: lest the Sabellian error should creep in, He immediately adds, And I do nothing of Myself; as if to say, I am not of Myself; the Son is God from the Father. Let not what follows, as the Father hath taught Me, I speak these things, suggest a carnal thought to any of you. Do not place as it were two men before your eyes, a Father speaking to his son, as you do when you speak to your sons. For what words could be spoken to the only Word? If the Father speaks in your hearts without sound, how does He speak to the Son? The Father speaks to the Son incorporeally, because He begat the Son incorporeally: nor did He teach Him, as having begotten Him untaught; rather the teaching Him, was the begetting Him knowing. For if the nature of truth be simple, to be, in the Son, is the same as to know. As then the Father gave the Son existence by begetting, so He gave Him knowledge also.