Catena Aurea on John 3:27–30: John Chrysostom

And see; the very argument by which they thought to have overthrown Christ, To whom, thou barest witness, he turns against them; Ye yourselves bear me witness, that I said, I am not the Christ; as if he said, If ye think my witness true, ye must acknowledge Him more worthy of honour than myself. He adds, But that I was sent before Him; that is to say, I am a servant, and perform the commission of the Father which sent me; my witness is not from favour or partiality; I say that which was given me to say.