Numbers 3:10-23
English Standard Version
11And the Lord spoke to Moses, saying,
12"Behold, I have taken the Levites from among the people of Israel instead of every firstborn who opens the womb among the people of Israel. The Levites shall be mine,
13for all the firstborn are mine. On the day that I struck down all the firstborn in the land of Egypt, I consecrated for my own all the firstborn in Israel, both of man and of beast. They shall be mine: I am the Lord."
14And the Lord spoke to Moses in the wilderness of Sinai, saying,
15"List the sons of Levi, by fathers ' houses and by clans; every male from a month old and upward you shall list."
16So Moses listed them according to the word of the Lord, as he was commanded.
17And these were the sons of Levi by their names: Gershon and Kohath and Merari.
18And these are the names of the sons of Gershon by their clans: Libni and Shimei.
19And the sons of Kohath by their clans: Amram, Izhar, Hebron, and Uzziel.
20And the sons of Merari by their clans: Mahli and Mushi. These are the clans of the Levites, by their fathers ' houses.