Exodus 6:23

Then He said to Moses, “Come up to Yahweh, you and Aaron, Nadab and Abihu and seventy of the elders of Israel, and you all shall worship at a distance.

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.

Now these are the generations of Aaron and Moses at the time when Yahweh spoke with Moses on Mount Sinai.

These then are the names of the sons of Aaron: Nadab the firstborn, and Abihu, Eleazar and Ithamar.

The sons of Levi were Gershon, Kohath, and Merari.

Now the divisions of the sons of Aaron were these: the sons of Aaron were Nadab, Abihu, Eleazar, and Ithamar.