9 And you shall give the Levites unto Aaron and to his sons: they are wholly given unto him out of the children of Israel.
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.
11 And the LORD spoke unto Moses, saying,
12 And I, behold, I have taken the Levites from among the children of Israel instead of all the firstborn that opens the womb among the children of Israel: therefore the Levites shall be mine;
13 Because all the firstborn are mine; for on the day that I struck all the firstborn in the land of Egypt I hallowed unto me all the firstborn in Israel, both man and animal: mine shall they be: I am the LORD.
14 And the LORD spoke unto 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 shall you number them.