Deuteronomy 19:2-4

International Standard Version

² You must reserve^[a] three cities within the land that the Lord your God is about to give you to possess. ³ Build roads throughout the land that the Lord your God is providing as an inheritance, and then divide it into three districts so that any killer may flee there.

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.