They were responsible for the Ark, the table, the menorah, the altars, and the implements of the Sanctuary used in service with them, the curtain and all involved with its use.
“Eleazar son of Aaron the kohen will have charge of the oil for the light, the fragrant incense, the regular grain offering and the anointing oil. He is to have charge of the Tabernacle and all that is in it, including its holy items and all its implements.”
The sons of the Gershonites are to do all their tasks, whether carrying or doing other work, according to the word of Aaron and his sons. You are to assign to them all that is their responsibility to carry.
He may assist his brothers in the Tent of Meeting to do their duties, but he himself will no longer do the work. Thus, you are to assign to the Levites their responsibilities.”