Numbers 3:17-20

Levi had three sons: Gershon, Kohath, and Merari, who were the ancestors of the clans that bear their names. Gershon had two sons: Libni and Shimei; Kohath had four sons: Amram, Izhar, Hebron, and Uzziel; and Merari had two sons: Mahli and Mushi. They were the ancestors of the families that bear their names.