1 Chronicles 6:1

And the sons of Levi; Gershon, Kohath, and Merari.

And these are the names of the sons of Levi according to their generations; Gershon, and Kohath, and Merari: and the years of the life of Levi were an hundred thirty and seven years.

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

And these are they that were numbered of the Levites after their families: of Gershon, the family of the Gershonites: of Kohath, the family of the Kohathites: of Merari, the family of the Merarites.

And David divided them into courses among the sons of Levi, namely, Gershon, Kohath, and Merari.