Deuteronomy 19:3-5

Darby Translation

³ Thou shalt prepare thee the way, and divide the territory of thy land, which Jehovah thy God giveth thee to inherit, into three parts, so that every slayer may flee thither.

⁴ And this is the case of the slayer who shall flee thither that he may live: he that smiteth his neighbour unwittingly, whom he hated not previously;

⁵ as when he goeth into the wood with his neighbour to hew wood, and his hand fetcheth a stroke with the axe to cut down the tree, and the iron slippeth from the handle, and lighteth upon his neighbour, that he die; such an one shall flee unto one of these cities, and live;