Reference: Abihu
Hastings
Second son of Aaron (Ex 6:23; Nu 3:2; 26:60; 1Ch 6:3; 24:1); accompanied Moses to the top of Sinai (Ex 24:1,9); admitted to the priest's office (Ex 28:1); slain along with his brother Nadab for offering strange fire (Le 10:1-2; Nu 3:4; 26:61; 1Ch 24:2).
See Verses Found in Dictionary
Aaron married Elisheba, the daughter of Amminadab, the sister of Nahshon, and she bore him Nadab and Abihu, Eleazar and Ithamar.
Jehovah said to Moses: You and Aaron, Nadab, Abihu, and seventy of Israel's elders come up the mountain to me and worship at a distance.
Moses and Aaron, together with Nadab and Abihu and the seventy leaders, went up the mountain.
Jehovah continued: Bring your brother Aaron and his sons Nadab, Abihu, Eleazar and Ithamar to you from all the Israelites. They will serve me as priests.
Aaron's sons Nadab and Abihu each took an incense burner. They put burning coals and incense in it. Then in Jehovah's presence they offered this unauthorized fire. A fire flashed from Jehovah and burned them. They died in the presence of Jehovah.
The names of Aaron's sons are Nadab (firstborn), Abihu, Eleazar, and Ithamar.
Nadab and Abihu died in Jehovah's presence because they offered unauthorized fire in his presence in the Desert of Sinai. They had no children. So only Eleazar and Ithamar served as priests during the lifetime of their father Aaron.
Aaron was the father of Nadab, Abihu, Eleazar, and Ithamar. Nadab and Abihu died because they offered unauthorized fire in Jehovah's presence.