Numbers 4:3-5

New Century Version

³ Count the men from thirty to fifty years old, all who come to serve in the Meeting Tent.

⁴ “The Kohathites are responsible for the most holy things in the Meeting Tent. ⁵ When the Israelites are ready to move, Aaron and his sons must go into the Holy Tent, take down the curtain, and cover the Ark of the Agreement with it.