New Defender's Study Bible Notes
2:21 deep sleep. The “deep sleep” was not simply an anesthetized state to prevent pain, since there was as yet no pain in the world. It was most likely ordained as a primeval picture of the future death of the second Adam, whose sacrificial death would result in the formation of His bride (II Corinthians 11:2; Ephesians 5:30-32).
2:21 ribs. The “rib” was actually the “side” of Adam (the Hebrew tsela occurs thirty-five times in the Old Testament, and is nowhere else translated “rib”). The side contained both “bone” and “flesh” (Genesis 2:23), but it may be that both are implied in the blood that would necessarily flow from the opened side. The “life of the flesh is in the blood” (Genesis 9:4; Leviticus 17:11) and a primeval blood “transfusion” would more perfectly fit the event as a type of the opened side of Christ on the cross (John 19:34-36). Even if the operation did actually extract a rib from Adam, this would not suggest that men should have one less rib than women, since “acquired characteristics” are not hereditable.