Numbers 7:3-8

3They brought their offering before the Lord, six covered carts and twelve oxen; a cart for each two of the leaders and an ox for each one; and they presented them before the tabernacle.

4Then the Lord spoke to Moses, saying,

5“Accept these things from them, so that they may be used in the service of the Tent of Meeting (tabernacle), and give them to the Levites, to each man according to his service.”

6So Moses took the carts and the oxen and gave them to the Levites.

7He gave two carts and four oxen to the sons of Gershon, according to their service [in transporting the tabernacle];

8and he gave four carts and eight oxen to the sons of Merari, according to their service [in transporting the tabernacle], under the supervision of Ithamar the son of Aaron, the [high] priest.