KJV: 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.
NASB: "All the service of the sons of the Gershonites, in all their loads and in all their work, shall be performed at the command of Aaron and his sons; and you shall assign to them as a duty all their loads.