Numbers 7:3-8

3They brought as their offering before the Lord six covered carts and twelve oxen, a cart from every two leaders and an ox from each one, and presented them in front of the tabernacle.

4The Lord said to Moses,

5“Accept these from them to be used in the work of the tent of meeting, and give this offering to the Levites, to each division according to their service.”

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

7He gave the Gershonites two carts and four oxen corresponding to their service,

8and gave the Merarites four carts and eight oxen corresponding to their service, under the direction of Ithamar son of Aaron the priest.