Deuteronomy 19:10-12

New Revised Standard Version, Anglicised

¹⁰ so that the blood of an innocent person may not be shed in the land that the Lord your God is giving you as an inheritance, thereby bringing blood-guilt upon you.

¹¹ But if someone at enmity with another lies in wait and attacks and takes the life of that person, and flees into one of these cities, ¹² then the elders of the killer’s city shall send to have the culprit taken from there and handed over to the avenger of blood to be put to death.