Numbers 3:16-20

And Moses numbered them according to the word of the LORD, as he was commanded.

And these were the sons of Levi by their names; Gershon, and Kohath, and Merari.

And these are the names of the sons of Gershon by their families; Libni, and Shimei.

And the sons of Kohath by their families; Amram, and Izehar, Hebron, and Uzziel.

And the sons of Merari by their families; Mahli, and Mushi. These are the families of the Levites according to the house of their fathers.