Num 35:24-27

24then the congregation shall judge between the slayer and the avenger of blood, in accordance with these ordinances;25and the congregation shall rescue the slayer from the avenger of blood. Then the congregation shall send the slayer back to the original city of refuge. The slayer shall live in it until the death of the high priest who was anointed with the holy oil.26But if the slayer shall at any time go outside the bounds of the original city of refuge,27and is found by the avenger of blood outside the bounds of the city of refuge, and is killed by the avenger, no bloodguilt shall be incurred.