Numbers 4:1-5
The Service of the Kohathites
4:1 Then the Lord spoke to Moses and Aaron:
4:2 “Take a census of the Kohathites from among the Levites, by their families and by their clans,
4:3 from thirty years old and upward to fifty years old, all who enter the company to do the work in the tent of meeting.
4:4 This is the service of the Kohathites in the tent of meeting, relating to the most holy things.
4:5 When it is time for the camp to journey, Aaron and his sons must come and take down the screening curtain and cover the ark of the testimony with it.