C. F. Keil and Franz Delitzsch on Numbers 3:7-8

Num 3:7-8

They were to keep the charge of Aaron and the whole congregation before the tabernacle, to attend to the service of the dwelling, i.e., to observe what Aaron (the priest) and the whole congregation were bound to perform in relation to the service at the dwelling-place of Jehovah. “To keep the charge:” see Num 1:53 and Gen 26:5. In Num 3:8 this is more fully explained: they were to keep the vessels of the tabernacle, and to attend to all that was binding upon the children of Israel in relation to them, i.e., to take the oversight of the furniture, to keep it safe and clean.