Put the headbands on their heads, and tie cloth belts around their waists. Aaron and his descendants will be priests in Israel, according to a rule that will continue from now on. This is how you will appoint Aaron and his sons as priests.
Moses said to Aaron and his remaining sons, Eleazar and Ithamar, “Eat the part of the grain offering that is left from the sacrifices offered by fire to the Lord, but do not add yeast to it. Eat it near the altar because it is most holy.
But only you and your sons may serve as priests. Only you may serve at the altar or go behind the curtain. I am giving you this gift of serving as a priest, and anyone else who comes near the Holy Place will be put to death.”
But Nadab and Abihu died in the presence of the Lord when they offered the wrong kind of fire before the Lord in the Desert of Sinai. They had no sons. So Eleazar and Ithamar served as priests during the lifetime of their father Aaron.