Genesis 3:21 - Joseph Benson’s Commentary on the Old and New Testaments

Unto Adam and his wife did God make By his own word, or by the ministry of angels; coats of skins Of beasts slain, either to show them what death is, or rather, as is more probable, in sacrifice to God, to prefigure the great sacrifice which, in the latter days, should be offered once for all. Thus the first animal that died was a sacrifice, or Christ in a figure. God clothed them: 1st, to defend them from the heat and cold, and other injuries of the air to which they were now to be exposed: 2d, to remind them of their fall, which had made that nakedness, which was before innocent and honourable, an occasion of sin and shame, and therefore it needed a covering. God also, by this act of kindness, probably intended to show his care even of fallen man, to encourage his hopes of mercy through a Mediator, and thereby to invite him to repentance.