They shall be ministers in my sanctuary, having oversight at the gates of the temple, and serving in the temple; they shall slay the burnt offering and the sacrifice for the people, and they shall attend on the people, to serve them.
And with you bring your brethren also, the tribe of Levi, the tribe of your father, that they may join you, and minister to you while you and your sons with you are before the tent of the testimony.
But Nadab and Abihu died before the Lord when they offered unholy 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.