Numbers 3:3; Numbers 3:4

3 These are the names of the sons of Aaron, the priests which were anointed, whom he consecrated to minister in the priest's office.

4 And Nadab and Abihu died before the LORD, when they offered strange fire before the LORD, in the wilderness of Sinai, and they had no children: and Eleazar and Ithamar ministered in the priest's office in the sight of Aaron their father.