Leviticus 10:10-12

10and 1to make a distinction between the holy and the profane, and between the unclean and the clean, 11and 2so as to teach the sons of Israel all the statutes which the Lord has spoken to them through Moses.”

12Then Moses spoke to Aaron, and to his surviving sons, 3Eleazar and Ithamar, “4Take the grain offering that is left over from the Lord’s offerings by fire and eat it as unleavened bread beside the altar, for it is most holy.