Numbers 3:6-16

6Bring the tribe of Levi near, and present them before Aaron the priest, that they may minister unto him;

7and they shall keep his charge, and the charge of the whole assembly, before the tent of meeting, to do the service of the tabernacle.

8And they shall keep all the utensils of the tent of meeting, and the charge of the children of Israel, to do the service of the tabernacle.

9And thou shalt give the Levites to Aaron and to his sons: they are wholly given to him out of the children of Israel.

10And Aaron and his sons shalt thou appoint that they may attend to their priest's office; and the stranger that cometh near shall be put to death.

11And Jehovah spoke to Moses, saying,

12And I, behold, I have taken the Levites from among the children of Israel instead of every firstborn that breaketh open the womb among the children of Israel, and the Levites shall be mine;

13for every firstborn is mine. On the day that I smote all the firstborn in the land of Egypt, I hallowed unto me all the firstborn in Israel, both of man and beast; mine shall they be: I am Jehovah.

14And Jehovah spoke to Moses in the wilderness of Sinai, saying,

15Number the sons of Levi according to their fathers' houses, after their families; every male from a month old and upward shalt thou number them.

16And Moses numbered them, according to the commandment of Jehovah, — as he had been commanded.