Numbers 26:61

But Nadab and Abihu died [in the presence of God] when they offered [in their ceremonial censers] strange [unholy, unacceptable, unauthorized] fire before the Lord.

Leviticus 10:1-2

Now Nadab and Abihu, the sons of Aaron, took their respective [ceremonial] censers, put fire in them, placed incense on it and offered strange (unauthorized, unacceptable) fire before the Lord, [an act] which He had not commanded them to do.

Numbers 3:4

But Nadab and Abihu died in the presence of the Lord when they offered strange (unholy, unacceptable, inappropriate) fire before the Lord in the Wilderness of Sinai; and they had no sons. So Eleazar and Ithamar served as priests in the presence and under the supervision of Aaron their father.

1 Chronicles 24:1-2

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

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