9 And thou shalt give the Levites to Aaron and to his sons: they are wholly given to him out of the children of Israel.
10 And thou shalt appoint Aaron and his sons, and they shall wait on their priest's office: and the stranger that cometh nigh shall be put to death.
11 And the LORD spoke to Moses, saying,
12 And I, behold, I have taken the Levites from among the children of Israel, instead of all the first-born that openeth the matrix among the children of Israel: therefore the Levites shall be mine;
13 Because all the first-born are mine; for on the day that I smote all the first-born in the land of Egypt, I hallowed to me all the first-born in Israel, both man and beast: mine they shall be: I am the LORD.
14 And the LORD spoke to Moses in the wilderness of Sinai, saying,
15 Number the children of Levi after the house of their fathers, by their families: every male from a month old and upward shalt thou number them.