Numbers 4:22-24

21st Century King James Version

²² “Take also the sum of the sons of Gershon, throughout the houses of their fathers, by their families.

²³ From thirty years old and upward until fifty years old shalt thou number them, all who enter in to perform the service, to do the work in the tabernacle of the congregation.

²⁴ This is the service of the families of the Gershonites, to serve and to bear burdens.