Deuteronomy 19:4-10 “Now this is the situation for any killer who flees there to live: suppose he strikes his friend unwittingly, not having hated him previously.

ISV⁽ⁱ⁾ ⁴ “Now this is the situation for any killer who flees there to live: suppose he strikes his friend unwittingly, not having hated him previously. ⁵ For instance, he may have accompanied his friend to go to a forest to cut trees. Then he swung his axe to cut some wood, but the ax head flew off the handle and hit his friend, so that he died. The killer may flee to one of these cities to live. ⁶ While the distance may be great and the angry avenger pursues the killer, he may overtake him and kill him, in which case there will be no justice in his death, because he did not hate his friend previously. ⁷ Therefore I am commanding you to reserve three cities.”
⁸ Increase the Cities of Refuge“Now if the LORD enlarges your territories just as he promised your ancestors and gives you all the land that he promised, ⁹ and if you are careful to observe all these commands that I am commanding you today—to love the LORD your God and to walk daily in his ways—then add three more cities in addition to these three cities. ¹⁰ You must not shed innocent blood on your land that the LORD your God is about to give you as an inheritance. Otherwise, you’ll be guilty of murder.”