Numbers 35:7-8

35:7 “So the total of the towns you will give the Levites is forty-eight. You must give these together with their grazing lands. 35:8 The towns you will give must be from the possession of the Israelites. From the larger tribes you must give more; and from the smaller tribes fewer. Each must contribute some of its own towns to the Levites in proportion to the inheritance allocated to each.