Numbers 35:26-28

“‘But if the man slayer shall at any time go beyond the border of his city of refuge, where he flees,

and the avenger of blood finds him outside of the border of his city of refuge, and the avenger of blood kills the man slayer; he shall not be guilty of blood,

because he should have remained in his city of refuge until the death of the high priest. But after the death of the high priest, the man slayer shall return into the land of his possession.