Aaron's sons Nadab and Abihu put coals of fire in their incense burners and sprinkled incense over it. In this way, they disobeyed the LORD by burning before him a different kind of fire than he had commanded.
So fire blazed forth from the LORD's presence and burned them up, and they died there before the LORD.
Then Moses said to Aaron, "This is what the LORD meant when he said, 'I will show myself holy among those who are near me. I will be glorified before all the people.'" And Aaron was silent.
Then Moses called for Mishael and Elzaphan, Aaron's cousins, the sons of Aaron's uncle Uzziel. He said to them, "Come and carry the bodies of your relatives away from the sanctuary to a place outside the camp."
So they came forward and carried them out of the camp by their tunics as Moses had commanded.
Then Moses said to Aaron and his sons Eleazar and Ithamar, "Do not mourn by letting your hair hang loose or by tearing your clothes. If you do, you will die, and the LORD will be angry with the whole community of Israel. However, the rest of the Israelites, your relatives, may mourn for Nadab and Abihu, whom the LORD has destroyed by fire.
References for Leviticus 10:6
But you are not to leave the entrance of the Tabernacle, under penalty of death, for the anointing oil of the LORD is upon you." So they did as Moses commanded.
References for Leviticus 10:7
Then the LORD said to Aaron,
"You and your descendants must never drink wine or any other alcoholic drink before going into the Tabernacle. If you do, you will die. This is a permanent law for you, and it must be kept by all future generations.
You are to distinguish between what is holy and what is ordinary, what is ceremonially unclean and what is clean.
And you must teach the Israelites all the laws that the LORD has given through Moses."
Then Moses said to Aaron and his remaining sons, Eleazar and Ithamar, "Take what is left of the grain offering after the handful has been presented to the LORD by fire. Make sure there is no yeast in it, and eat it beside the altar, for it is most holy.
It must be eaten in a sacred place, for it has been given to you and your descendants as your regular share of the offerings given to the LORD by fire. These are the commands I have been given.
But the breast and thigh that were lifted up may be eaten in any place that is ceremonially clean. These parts have been given to you and to your sons and daughters as your regular share of the peace offerings presented by the people of Israel.
The thigh and breast that are lifted up must be lifted up to the LORD along with the fat of the offerings given by fire. Then they will belong to you and your descendants forever, just as the LORD has commanded."
When Moses demanded to know what had happened to the goat of the sin offering, he discovered that it had been burned up. As a result, he became very angry with Eleazar and Ithamar, Aaron's remaining sons.
"Why didn't you eat the sin offering in the sanctuary area?" he demanded. "It is a holy offering! It was given to you for removing the guilt of the community and for making atonement for the people before the LORD.
Since the animal's blood was not taken into the Holy Place, you should have eaten the meat in the sanctuary area as I ordered you."
Then Aaron answered Moses on behalf of his sons. "Today my sons presented both their sin offering and their burnt offering to the LORD," he said. "This kind of thing has also happened to me. Would the LORD have approved if I had eaten the sin offering today?"
And when Moses heard this, he approved.