Numbers 1:4

1:4 And to help you there is to be a man from each tribe, each man the head of his family.

Numbers 3:20

3:20 The sons of Merari by their families were Mahli and Mushi. These are the families of the Levites by their clans.

Numbers 4:2

4:2 “Take a census of the Kohathites from among the Levites, by their families and by their clans,

Numbers 4:22

4:22 “Also take a census of the Gershonites, by their clans and by their families.

Numbers 4:40

4:40 those of them numbered by their families, by their clans, were 2,630.