Numbers 35:25-27

LITV(i) 25 And the congregation shall deliver the manslayer out of the avenger of blood's hand. And the congregation shall return him to the city of refuge to which he had fled, and he shall live in it until the high priest dies, he who was anointed with the holy oil. 26 But if the manslayer at all goes out from the border of the city of his refuge, there to which he has fled, 27 and the avenger of blood finds him outside the border of the city of his refuge, and the avenger of blood kills the manslayer, there shall be no blood guiltiness to him,