Numbers 26:61

Christian Standard Bible

but Nadab and Abihu died when they presented unauthorized fire before the Lord.

Cross References

Numbers 3:4

But Nadab and Abihu died in the Lord’s presence when they presented unauthorized fire  before the Lord in the Wilderness of Sinai, and they had no sons. So Eleazar and Ithamar served as priests under the direction of Aaron their father.

Exodus 6:23

Aaron married Elisheba, daughter of Amminadab  and sister of Nahshon. She bore him Nadab and Abihu, Eleazar and Ithamar.