Numbers 4:2 in the King James Version
Take the sum of the sons of Kohath from among the sons of Levi, after their families, by the house of their fathers,
Context
1 The LORD spoke to Moses and to Aaron, saying,
2 “Take a census of the sons of Kohath from among the sons of Levi, by their families, by their fathers’ houses,
3 from thirty years old and upward even until fifty years old, all who enter into the service to do the work in the Tent of Meeting.