But Nadab and Abihu died before the Lord when they offered unauthorized fire before the Lord in the wilderness of Sinai, and they had no children. So Eleazar and Ithamar served as priests in the lifetime of Aaron their father.
And you and your sons with you shall guard your priesthood for all that concerns the altar and that is within the veil; and you shall serve. I give your priesthood as a gift, and any outsider who comes near shall be put to death.”
Moses spoke to Aaron and to Eleazar and Ithamar, his surviving sons: “Take the grain offering that is left of the Lord’s food offerings, and eat it unleavened beside the altar, for it is most holy.
and you shall gird Aaron and his sons with sashes and bind caps on them. And the priesthood shall be theirs by a statute forever. Thus you shall ordain Aaron and his sons.