Gregory the Great
Catena Aurea · Johannesevangelium 8
Then said the Jews unto him. Thou art not yet fifty years old, and hast thou seen Abraham? Jesus said unto them, Verily, verily, I say unto you, Before Abraham was, I am. Then took they up stones to cast at him: but Jesus hid himself, and went out of the temple, going through the midst of them, and so passed by.
(ut sup.) Our Saviour mildly draws them away from their carnal view, to the contemplation of His Divinity; Jesus said unto them, Verily, verily, I say unto you, Before Abraham was, I am. Before is aparticle of past time, am, of present. Divinity has no past or future, but always the present; and therefore He does not say, Before Abraham was, I was: but, Before Abraham was, I am: (Exod. 3:14) as it is in Exodus, I am that I am. Before and after might be said of Abraham with reference to different periods of his life; to be, in the present, is said of the truth only.