Numbers 3:23
The Gershonite clans camped behind the Holy Tent on the west side.
From Gershon are descended the Libnite and the Shimeite clans; these are the Gershonite clans.
Merari’s sons by their clans: Mahli and Mushi. These are Levi’s clans, grouped according to their ancestral families.
“You are to take a census of the sons of Levi by families and clans; all the males of the age of one month and over must be counted.”