I said therefore unto you, that ye shall die in your sins: for if ye believe not that I am he, ye shall die in your sins.

People's New Testament

8:23,24 I am from above. He shows more clearly that he returns to heaven, where they never can enter on account of their sins. This leads them to ask:

Wesley's Notes

8:24 If ye believe not that I AM - Here (as in John 8:58) our Lord claims the Divine name, I AM, Exod 3:14. But the Jews, as if he had stopped short, and not finished the sentence, answered, Who art thou?

Scofield Reference Notes

Margin sins

Sin. See Scofield Note: "Rom 3:23".

Jamieson-Fausset-Brown Bible Commentary

24. if ye believe not that I am he, ye shall die in your sins-They knew well enough what He meant (Mr 13:6, Greek; compare Mt 24:5). But He would not, by speaking it out, give them the materials for a charge for which they were watching. At the same time, one is irresistibly reminded by such language, so far transcending what is becoming in men, of those ancient declarations of the God of Israel, "I AM He" (De 32:39; Isa 43:10, 13; 46:4; 48:12). See on [1811]Joh 6:20.

Matthew Henry's Concise Commentary

8:21-29 Those that live in unbelief, are for ever undone, if they die in unbelief. The Jews belonged to this present evil world, but Jesus was of a heavenly and Divine nature, so that his doctrine, kingdom, and blessings, would not suit their taste. But the curse of the law is done away to all that submit to the grace of the gospel. Nothing but the doctrine of Christ's grace will be an argument powerful enough, and none but the Spirit of Christ's grace will be an agent powerful enough, to turn us from sin to God; and that Spirit is given, and that doctrine is given, to work upon those only who believe in Christ. Some say, Who is this Jesus? They allow him to have been a Prophet, an excellent Teacher, and even more than a creature; but cannot acknowledge him as over all, God blessed for evermore. Will not this suffice? Jesus here answers the question. Is this to honour him as the Father? Does this admit his being the Light of the world, and the Life of men, one with the Father? All shall know by their conversion, or in their condemnation, that he always spake and did what pleased the Father, even when he claimed the highest honours to himself.