Deuteronomy 21:1

Land. The Jewish doctors hence infer, that if the corpse was found hanging or drowned &c., or nearer a town of the Gentiles than one of the Israelites, this law did not oblige. They are so exact as to dispute whether the distance must be measured from the nose or from the naval of the deceased. (Selden, Syned. iii. 7.) But the law shews us, that the author of the murder must be discovered, if possible, as the crime is so grievous as, in a manner, to defile the land, and draw down the vengeance of God, if it be carelessly left unpunished. (Calmet)