Numbers 7:3-8

3and brought their offerings before the Lord, six wagons and twelve oxen, a wagon for every two of the chiefs, and for each one an ox. They brought them before the tabernacle.

4Then the Lord said to Moses,

5"Accept these from them, that they may be used in the service of the tent of meeting, and give them to the Levites, to each man according to his service."

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

7Two wagons and four oxen he gave to the sons of Gershon, according to their service.

8And four wagons and eight oxen he gave to the sons of Merari, according to their service, under the direction of Ithamar the son of Aaron the priest.