Numbers 3:2-4

21These then are the names of the sons of Aaron: Nadab the firstborn, and Abihu, Eleazar and Ithamar. 3These are the names of the sons of Aaron, the 2anointed priests, whom he 3ordained to serve as priests. 44But 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. So Eleazar and Ithamar served as priests 5in the lifetime of their father Aaron.