Numbers 35:2-8

35:2 “Instruct the Israelites to give the Levites towns to live in from the inheritance the Israelites will possess. You must also give the Levites grazing land around the towns. 35:3 Thus they will have towns in which to live, and their grazing lands will be for their cattle, for their possessions, and for all their animals. 35:4 The grazing lands around the towns that you will give to the Levites must extend to a distance of 500 yards from the town wall.

35:5 “You must measure from outside the wall of the town on the east 1,000 yards, and on the south side 1,000 yards, and on the west side 1,000 yards, and on the north side 1,000 yards, with the town in the middle. This territory must belong to them as grazing land for the towns. 35:6 Now from these towns that you will give to the Levites you must select six towns of refuge to which a person who has killed someone may flee. And you must give them forty-two other towns.

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.