Augustine of Hippo
Catena Aurea · Johannesevangelium 8
The Pharisees therefore said unto him, Thou bearest record of thyself; thy record is not true. Jesus answered and said unto them, Though I bear record of myself, yet my record is true: for I know whence I came, and whither I go; but ye cannot tell whence I come, and whither I go. Ye judge after the flesh; I judge no man. And yet if I judge, my judgment is true: for I am not alone, but I and the Father that sent me. It is also written in your law, that the testimony of two men is true. I am one that bear witness of myself, and the Father that sent me beareth witness of me.
(Tract. xxxvi. 7) But if the Father is with Thee, how did He send Thee? O Lord, Thy mission is Thy incarnation. Christ was here according to the flesh without withdrawing from the Father, because the Father and the Son are every where. Blush, thou Sabellian; our Lord doth not say, I am the Father, and I the self-same person am the Son; but, I am not alone, because the Father is with Me. Make a distinction then of persons, and distinction of intelligences: acknowledge that the Father is the Father, the Son the Son: but beware of saying, that the Father is greater, the Son less. Theirs is one substance, one coeternity, perfect equality. Therefore, He says, My judgment is true, because I am the Son of God. But that thou mayest understand how that the Father is with Me, it is not for the Son ever to leave the Father. I have taken up the form of a servant; but I have not lost the form of God. He had spoken of judgment: now He speaks of witness: It is also written in your law, that the testimony of two men is true.