Numbers 35:13-15

35:13 These towns that you must give shall be your six towns for refuge.

35:14 “You must give three towns on this side of the Jordan, and you must give three towns in the land of Canaan; they must be towns of refuge. 35:15 These six towns will be places of refuge for the Israelites, and for the foreigner, and for the settler among them, so that anyone who kills any person accidentally may flee there.

Joshua 20:7-9

20:7 So they selected Kedesh in Galilee in the hill country of Naphtali, Shechem in the hill country of Ephraim, and Kiriath Arba (that is, Hebron) in the hill country of Judah. 20:8 Beyond the Jordan east of Jericho they selected Bezer in the desert on the plain belonging to the tribe of Reuben, Ramoth in Gilead belonging to the tribe of Gad, and Golan in Bashan belonging to the tribe of Manasseh. 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.