Unauthorized

On this altar you must not offer unauthorized incense or a burnt offering or grain offering; nor are you to pour a drink offering on it.

Now Aaron’s sons Nadab and Abihu took their censers, put fire in them and added incense, and offered unauthorized fire before the LORD, contrary to His command.

Nadab and Abihu, however, died in the presence of the LORD when they offered unauthorized fire before the LORD in the Wilderness of Sinai. And since they had no sons, only Eleazar and Ithamar served as priests during the lifetime of their father Aaron.

…but Nadab and Abihu died when they offered unauthorized fire before the LORD.