Joshua 20:3

20:3 Anyone who accidentally kills someone can escape there; these cities will be a place of asylum from the avenger of blood.

Joshua 8:20

8:20 When the men of Ai turned around, they saw the smoke from the city ascending into the sky and were so shocked they were unable to flee in any direction. In the meantime the men who were retreating to the desert turned against their pursuers.

Joshua 20:9

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.