Numbers 3:8-10 Modern English Version (MEV)
8 They will keep all the instruments of the tent of meeting, and attend to the needs of the children of Israel, to do the service of the tabernacle. 9 You will give the Levites to Aaron and to his sons. They are wholly given to him from the children of Israel. 10 You will appoint Aaron and his sons, and they will attend to their priesthood, and the foreigner that approaches will be put to death.