Duties of the Sons of Kohath (Numbers 4)

      By their families, by heir fathers' house.  From thirty years old and above, even to fifty years old, all who enter the service to do the work in the tabernacle of meeting.  This is the services of the sons of Kohath in the tabernacle of meeting, relating to the most holy things:  When the camp prepares to journey, Aaron and his sons shall come, and they shall take down the covering veil and cover the ark of the Testimony with it.