Ellicott's Commentary for English Readers - Genesis 3:21
(21) Coats of skins.—Animals, therefore, were killed even in Paradise; nor is it certain that man’s diet was until the flood entirely vegetarian (see Note on Genesis 1:29). Until sin entered the world no sacrifices could have been offered; and if, therefore, these were the skins of animals offered in sacrifice, as many suppose, Adam must in some way, immediately after the fall, have been taught that without shedding of blood is no remission of sin, but that God will accept a vicarious... read more
Ellicott's Commentary for English Readers - Genesis 3:1-24
EXCURSUS C: ON THE DURATION OF THE PARADISIACAL STATE OF INNOCENCE.The Bereshit Rabba argues that Adam and Eve remained in their original state of innocence for six hours only. Others have supposed that the events recorded in Genesis 2:4 to Genesis 3:24 took place in the course of twenty-four hours, and suppose that this is proved by what is said in Genesis 2:4, that the earth and heavens, with Adam and the garden, were all made in one day, before the end of which they suppose that he fell.... read more