Numbers 35:6-8

6“Six of the towns you give the Levites will be cities of refuge, where a person who has accidentally killed someone can flee for safety. In addition, give them forty-two other towns.

7In all, forty-eight towns with the surrounding pastureland will be given to the Levites.

8These towns will come from the property of the people of Israel. The larger tribes will give more towns to the Levites, while the smaller tribes will give fewer. Each tribe will give property in proportion to the size of its land.”