Joshua 20:9--21:1

20:9 These were the cities of refuge appointed for all the Israelites and for resident foreigners living among them. Anyone who accidentally killed someone could escape there and not be executed by the avenger of blood, at least until his case was reviewed by the assembly.

Levitical Cities

21:1 The tribal leaders of the Levites went before Eleazar the priest and Joshua son of Nun and the Israelite tribal leaders