Numbers 16:5, 7, 10, 35, 40, 46-48

and he spoke to Korah and all his company, saying, “Tomorrow morning the LORD will show who is His and who is holy, and will cause him to come near to Him. That one whom He chooses He will cause to come near to Him.

put fire in them and put incense in them before the LORD tomorrow, and it shall be that the man whom the LORD chooses is the holy one. You take too much upon yourselves, you sons of Levi!”

and that He has brought you near to Himself, you and all your brethren, the sons of Levi, with you? And are you seeking the priesthood also?

And a fire came out from the LORD and consumed the two hundred and fifty men who were offering incense.

to be a memorial to the children of Israel that no outsider, who is not a descendant of Aaron, should come near to offer incense before the LORD, that he might not become like Korah and his companions, just as the LORD had said to him through Moses.

So Moses said to Aaron, “Take a censer and put fire in it from the altar, put incense on it, and take it quickly to the congregation and make atonement for them; for wrath has gone out from the LORD. The plague has begun.” Then Aaron took it as Moses commanded, and ran into the midst of the assembly; and already the plague had begun among the people. So he put in the incense and made atonement for the people. And he stood between the dead and the living; so the plague was stopped.