Numbers 4:23-26

23from thirty to fifty years old, counting everyone who comes to serve in the work at the Tent of Meeting.

24This is the service of the Gershonite clans regarding work and transport: 25They are to carry the curtains of the tabernacle, the Tent of Meeting with the covering of fine leather over it, the curtains for the entrance to the Tent of Meeting, 26the curtains of the courtyard, and the curtains for the entrance at the gate of the courtyard that surrounds the tabernacle and altar, along with their ropes and all the equipment for their service. The Gershonites will do all that needs to be done with these items.