Joshua 20:8-9

8And beyond the Jordan at Jericho eastward, they assigned Bezer in the wilderness in the plain out of the tribe of Reuben, and Ramoth in Gilead out of the tribe of Gad, and Golan in Bashan out of the tribe of Manasseh. 9These were the appointed cities for all the children of Israel, and for the stranger that sojourneth among them, that whosoever killeth any person unwittingly might flee thither, and not die by the hand of the avenger of blood, until he stood before the congregation.