Deuteronomy 19:1-7

1“1When the Lord your God cuts off the nations whose land the Lord your God is giving you, and you dispossess them and settle in their cities and in their houses, 22you shall set aside for yourself three cities in the midst of your land which the Lord your God is giving you to 3possess. 3You shall prepare the 4roads for yourself, and divide into three regions the territory of your land which the Lord your God will give you as an inheritance, 5so that anyone who commits manslaughter may flee there.

4“6Now this is the case of the one who commits manslaughter, who may flee there and live: when he 7kills his friend 8unintentionally, 9not hating him previously-- 5as when a person goes into the forest with his friend to cut wood, and his hand 10swings the axe to cut down the tree, and the iron head slips off the 11handle and 12strikes his friend so that he dies--he may flee to one of these cities and live. 6Otherwise, the avenger of blood might pursue 13him 14in the heat of his anger, and overtake him because the way is long, and 15take his life, though he was not sentenced to death since he had not hated him previously. 7Therefore I command you, saying, ‘You shall set aside for yourself three cities.’