Numbers 3:36-37

3:36 The appointed responsibilities of the Merarites included the frames of the tabernacle, its crossbars, its posts, its sockets, its utensils, plus all the service connected with these things, 3:37 and the pillars of the courtyard all around, with their sockets, their pegs, and their ropes.

Numbers 7:8-9

7:8 and he gave four carts and eight oxen to the Merarites, as their service required, under the authority of Ithamar son of Aaron the priest. 7:9 But to the Kohathites he gave none, because the service of the holy things, which they carried on their shoulders, was their responsibility.