Numbers 3:4-6

Wycliffe Bible

⁴ Nadab and Abihu [died], when they offered alien fire in the sight of the Lord, in the desert of Sinai, (and they) were dead without free children; and Eleazar and Ithamar were set in priesthood before Aaron their father. (But then Nadab and Abihu were killed, when they offered unholy fire before the Lord, in the Sinai Desert, and they died before having any children; and so Eleazar and Ithamar were ordained in the priesthood in the sight of their father Aaron.)

⁵ And the Lord spake to Moses, saying,

⁶ Present thou the lineage of Levi, and make it to stand in the sight of Aaron, the priest, that they minister to him; (Present thou the tribe of Levi, and make them to stand before Aaron, the priest, to serve him;)