John 7:27

This man. They were acquainted with the earthly ancestry of Jesus. “Is not this the carpenter’s son?” they once said (Matt. 13:55). However, they appeared to be ignorant of His birth in Bethlehem (John 7:42).

When Christ cometh. For the title Christ, signifying Messiah, see on Matt. 1:1; cf. John 1:41. The statement, “No man knoweth whence he is,” must not be understood as meaning ignorance concerning the descent of Christ from the tribe of David, for with this fact the Jews were familiar (Matt. 22:42). Nor does it imply ignorance concerning Messiah’s birthplace, for when Herod demanded of the chief priests and of the scribes where Christ should be born, they answered, “In Bethlehem of Judaea” (Matt. 2:4, 5). There is probably a reference here to a popular belief concerning the Messiah reflected in a saying of Trypho the Jew: “But Christ — if He has indeed been born, and exists anywhere — is unknown, and does not even know Himself and has no power until Elias come to anoint Him, and make Him manifest to all” (Justin Martyr, Dialogue With Trypho 8).