The sons of Aaron were Nadab the first-born, Abihu, Eleazar, and Ithamar

Nadab and Abihu died in the LORD's presence when they offered unauthorized fire before him in the Sinai wilderness. Since they didn't have their own children, Eleazar and Ithamar ministered as priests under the authority of Aaron their father.

To Aaron were born Nadab, Abihu, Eleazar, and Ithamar.

But Nadab and Abihu died when they offered unauthorized fire in the LORD's presence.