Read Numbers 4:27 Using Other Translations
At the appointment of Aaron and his sons shall be all the service of the sons of the Gershonites, in all their burdens, and in all their service: and ye shall appoint unto them in charge all their burdens.
All the service of the sons of the Gershonites shall be at the command of Aaron and his sons, in all that they are to carry and in all that they have to do. And you shall assign to their charge all that they are to carry.
Aaron and his sons will direct the Gershonites regarding all their duties, whether it involves moving the equipment or doing other work. They must assign the Gershonites responsibility for the loads they are to carry.