Numbers 4:2-4

New Revised Standard Version, Anglicised Catholic Edition

² Take a census of the Kohathites separate from the other Levites, by their clans and their ancestral houses, ³ from thirty years old up to fifty years old, all who qualify to do work relating to the tent of meeting. ⁴ The service of the Kohathites relating to the tent of meeting concerns the most holy things.