Numbers 35:11; Numbers 35:25-28

11 select some towns to be your cities of refuge, to which a person who has killed someone accidentally may flee.
25 The assembly must protect the one accused of murder from the avenger of blood and send the accused back to the city of refuge to which they fled. The accused must stay there until the death of the high priest, who was anointed with the holy oil. 26 “ ‘But if the accused ever goes outside the limits of the city of refuge to which they fled 27 and the avenger of blood finds them outside the city, the avenger of blood may kill the accused without being guilty of murder. 28 The accused must stay in the city of refuge until the death of the high priest; only after the death of the high priest may they return to their own property.