Right after that amazing moment, Aaron’s sons Nadab and Abihu each took a fire pan, put fire in it, and laid incense on it. They offered “alien fire,” something God had not commanded. Fire came forth from God and consumed them, and they died.
Moses said to Aaron that God had meant, “Through those near to Me I show Myself holy, and gain glory before all the people.” Aaron did not argue; he stayed silent. Moses called Mishael and Elzaphan, relatives of Aaron, and told them to carry the bodies outside the camp, and they did.
Moses warned Aaron and his remaining sons, Eleazar and Ithamar, not to tear their clothes or leave the entrance of the Tent of Meeting, because God’s anointing oil was on them, even though the rest of Israel could mourn. Then God spoke to Aaron: no wine or intoxicant when entering the Tent of Meeting, so the priests could tell the difference between sacred and ordinary, and between impure and pure, and teach the people God’s laws.
Later Moses questioned why the goat of the purgation offering had been burned instead of eaten in the sacred area. Aaron explained what had happened that day, and Moses accepted his answer.