Numbers 35:27-29

Evangelical Heritage Version

²⁷ and the avenger of blood finds him outside of the border of his city of refuge, and the avenger of blood kills the person who has killed someone, the avenger will not be guilty of bloodshed, ²⁸ because the person who has killed someone should have stayed in his city of refuge until the death of the high priest. But after the death of the high priest he may return to the land that is his possession.

²⁹ These things will be a legal statute for you throughout your generations wherever you live.