Numbers 7:3-8

3and they brought their oblation before Jehovah, six covered wagons, and twelve oxen; a wagon for every two of the princes, and for each one an ox: and they presented them before the tabernacle.

4And Jehovah spake unto Moses, saying,

5Take it of them, that they may be used in doing the service of the tent of meeting; and thou shalt give them unto the Levites, to every man according to his service.

6And Moses took the wagons and the oxen, and gave them unto the Levites.

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

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