Albert Barnes Commentary John 8:58

"Jesus said unto them, Verily, verily, I say unto you, Before Abraham was born, I am." — John 8:58 (ASV)

Truly, truly. This is an expression used only in John. It is a strong affirmation, denoting particularly the great importance of what was about to be affirmed. See Barnes on John 3:5.

Before Abraham was. Before Abraham lived.

I am. The expression "I am," though in the present tense, is clearly designed to refer to a past time. Thus, in Psalm 90:2, From everlasting to everlasting you are God. Applied to God, it denotes continued existence without respect to time, as far as He is concerned. We divide time into the past, the present, and the future.

The expression, applied to God, denotes that He does not measure His existence in this manner; rather, the word by which we express the present signifies His continued and unchanging existence. Therefore, He assumes as His name I AM and I AM THAT I AM (Exodus 3:14). Compare Isaiah 44:6 and Isaiah 47:8.

There is a remarkable similarity between the expression Jesus used here and the one used in Exodus to denote the name of God. The manner in which Jesus used it would strikingly suggest the application of the same language to God.

The question here concerned His pre-existence. The Jews' objection was that He was not fifty years old and therefore could not have seen Abraham. Jesus replied to this that He existed before Abraham.

Since in His human nature He was not yet fifty years old and, as a man, could not have existed before Abraham, this declaration must refer to another nature. This passage proves that while He was a man, He was also endowed with another nature existing before Abraham, to which He applied the term I AM (a term familiar to the Jews as expressive of God's existence). This declaration corresponds to John's affirmation (John 1:1) that He was in the beginning with God and was God.

This affirmation by Jesus is one of the proofs on which John relies to demonstrate that He was the Messiah (John 20:31); indeed, establishing this was the purpose of writing this book.