Numbers 16:40

then you shall say to them, ‘Because the waters of the Jordan were cut off before the ark of the covenant of Yahweh; when it crossed the Jordan, the waters of the Jordan were cut off.’ So these stones shall become a memorial to the sons of Israel forever.”

And they stood against Uzziah the king and said to him, “It is not for you, Uzziah, to burn incense to Yahweh, but for the priests, the sons of Aaron who are set apart as holy to burn incense. Get out of the sanctuary, for you have been unfaithful and will have no honor from Yahweh God.”

These searched in their genealogical records, but they could not be found; therefore they were considered unclean and excluded from the priesthood.

but the chamber which faces toward the north is for the priests who keep the responsibility of the altar. These are the sons of Zadok, who from the sons of Levi come near to Yahweh to minister to Him.”

‘And you shall give to the Levitical priests who are from the seed of Zadok, who draw near to Me to minister to Me,’ declares Lord Yahweh, ‘a bull from the herd for a sin offering.

And no one takes this honor to himself, but receives it when he is called by God, even as Aaron was.