Numbers 4:3-5

New Revised Standard Version, Anglicised Catholic Edition

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.

⁵ When the camp is to set out, Aaron and his sons shall go in and take down the screening curtain, and cover the ark of the covenant^[a] with it;