Deuteronomy 19:2-4

Darby Translation

² thou shalt separate three cities for thyself in the midst of thy land, which Jehovah thy God giveth thee to possess.

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;