The LORD said to Moses, “Come up to me on this mountain. Bring along Aaron, as well as his two sons Nadab and Abihu, and seventy of Israel's leaders. They must worship me at a distance,
Moses told Aaron and his two sons, Eleazar and Ithamar: The grain sacrifice that was offered to give thanks to the LORD is very holy. So make bread without yeast from the part that wasn't sent up in smoke and eat it beside the altar.
But only you and your sons can serve as priests at the altar and in the most holy place. Your work as priests is a gift from me, and anyone else who tries to do that work must be put to death.
But the LORD killed Nadab and Abihu in the Sinai Desert when they used fire that was unacceptable in their offering to the LORD. And because Nadab and Abihu had no sons, only Eleazar and Ithamar served as priests with their father Aaron.