Numbers 3:4-6

English Standard Version

^4 (A)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.

Duties of the Levites

⁵ And the Lord spoke to Moses, saying, ^6 (B)“Bring the tribe of Levi near, and set them before Aaron the priest, that they may minister to him.