Numbers 3:2

And Aaron took Elisheba, the daughter of Amminadab, the sister of Nahshon, as a wife, and she bore him Nadab and Abihu, Eleazar and Ithamar.

Then Nadab and Abihu, the sons of Aaron, took their respective firepans and put fire in them. Then they placed incense on it and offered strange fire before Yahweh, which He had not commanded them.

Then Moses spoke to Aaron and to his remaining sons, Eleazar and Ithamar, “Take the remaining grain offering from the offerings to Yahweh by fire and eat it unleavened beside the altar, for it is most holy.

And to Aaron were born Nadab and Abihu, Eleazar and Ithamar.