Numbers 3:10
And you shall appoint Aaron and his sons, and they shall wait on their priest's office: and the stranger that comes near shall be put to death.
Nave's Topical Index—AKJV

Numbers 16:1
Now Korah, the son of Izhar, the son of Kohath, the son of Levi, and Dathan and Abiram, the sons of Eliab, and On, the son of Peleth, sons of Reuben, took men:
Nave's Topical Index—AKJV

Numbers 18:7
Therefore you and your sons with you shall keep your priest's office for everything of the altar, and within the veil; and you shall serve: I have given your priest's office to you as a service of gift: and the stranger that comes near shall be put to death.
Nave's Topical Index—AKJV

2 Chronicles 26:18
And they withstood Uzziah the king, and said to him, It appertains not to you, Uzziah, to burn incense to the LORD, but to the priests the sons of Aaron, that are consecrated to burn incense: go out of the sanctuary; for you have trespassed; neither shall it be for your honor from the LORD God.
Nave's Topical Index—AKJV