Num 3:10, 18:1-5, 1Ch 6:48-49 | ESV | STEP | And you shall appoint Aaron and his sons , and they shall guard their priesthood . But if any outsider comes near, he shall be put to death .

Numbers 3:10

10 And you shall appoint Aaron and his sons, and ^athey shall guard their priesthood. But if ^bany outsider comes near, he shall be put to death.”

Numbers 18:1-5

Duties of Priests and Levites

1 So the Lord said to Aaron, “You and your sons and your father’s house with you shall ^cbear iniquity connected with the sanctuary, ^dand you and your sons with you shall bear iniquity connected with your priesthood. 2 And with you bring your brothers also, the tribe of Levi, the tribe of your father, that they may ^ejoin you and ^fminister to you while you and your sons with you are before the tent of the testimony. 3 They shall keep guard over you and ^gover the whole tent, ^hbut shall not come near to the vessels of the sanctuary or to the altar ⁱlest they, and you, die. 4 They shall join you and keep guard over the tent of meeting for all the service of the tent, ^jand no outsider shall come near you. 5 And you shall ^kkeep guard over the sanctuary and over the altar, ^lthat there may never again be wrath on the people of Israel.

1 Chronicles 6:48-49

48 And their brothers the Levites were appointed for all the service of the tabernacle of the house of God.

49 But Aaron and his sons made offerings ^mon the altar of burnt offering and on ⁿthe altar of incense for all the work of the Most Holy Place, and ^oto make atonement for Israel, according to all that Moses the servant of God had commanded.