Origen, on Exod 13:2

“Sanctify unto me every firstborn that openeth the womb among the children of Israel, as well of men as of beasts: for they are all mine.”

“Males were sacred because they opened their mothers' wombs. They were offered before the altar of the Lord. Scripture says, "Every male that opens the womb.…" This phrase has a spiritual meaning. For you might say that "every male is brought forth from the womb" but does not open the womb of his mother in the way that the Lord Jesus did. In the case of every other woman, it is not the birth of an infant but intercourse with a man that opens the womb. But the womb of the Lord's mother was opened at the time when her offspring was brought forth, because before the birth of Christ a male did not even touch her womb, holy as it was and deserving of all respect.”

Imported from an open dataset — not yet checked against the printed edition.