Numbers 3:2-4

New Revised Standard Version, Anglicised Catholic Edition

² These are the names of the sons of Aaron: Nadab the firstborn, and Abihu, Eleazar, and Ithamar; ³ these are the names of the sons of Aaron, the anointed priests, whom he ordained to minister as priests. ⁴ 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. Eleazar and Ithamar served as priests in the lifetime of their father Aaron.