Deuteronomy 21:2-4

New Century Version

² Your elders and judges should go to where the body was found, and they should measure how far it is to the nearby cities. ³ The elders of the city nearest the body must take a young cow that has never worked or worn a yoke, ⁴ and they must lead her down to a valley that has never been plowed or planted, with a stream flowing through it. There they must break the young cow’s neck.