Deuteronomy 19:3-5

New Catholic Bible

³ Build roads to them, and divide the land that the Lord, your God, is giving you as an inheritance into three parts so that anyone who has killed another can flee to them. ⁴ This is the regulation concerning the one who has killed another and flees there to save his life: one who kills his neighbor unintentionally, who did not previously bear him ill will, ⁵ for example, when a man goes into the woods with his neighbor to cut wood, and as he is swinging the ax to cut down a tree, and the head of the ax flies off and kills the neighbor. That man may flee to one of the cities to save his life.