They were responsible for taking care of the frames of the tent. They took care of its crossbars, posts and bases. They took care of all its supplies. In fact, they had to take care of everything connected with the use of all those things.
Moses, Aaron and Aaron’s sons had to camp to the east of the holy tent. They had to camp toward the sunrise in front of the tent of meeting. They were responsible for taking care of the sacred tent. They had to do it for the Israelites. Anyone else who approached the tent would be put to death.