Charles Ellicott Commentary John 8:57

"The Jews therefore said unto him, Thou art not yet fifty years old, and hast thou seen Abraham?" — John 8:57 (ASV)

You are not yet fifty years old.—There is no reason to doubt that we have the correct reading here, though some, from Chrysostom onward, have sought to avoid what seemed to them a difficulty by substituting “forty” for “fifty.” Others, including the “Elders who in Asia conferred with John, the Lord’s disciple,” have held that our Lord was between forty and fifty years of age at the time of his public ministry.

We know this from the testimony of Irenaeus, who appears to have this very passage in his mind, for he says, “As the gospel and all the Elders witness” (Lib. 2 chap. 22 § 5; Oxford Translation, p. 160). But “fifty years” was the period of full manhood (Numbers 4:3; Numbers 4:39; Numbers 8:24). This is expressed in round numbers, and there is no concern to be more exact in comparison with the two thousand years which had passed since the close of Abraham’s earthly life. The thought is, “You are still a young man, and have you seen Abraham who died twenty centuries ago?”