Deuteronomy 19:3 KJV
Thou shalt prepare thee a way, and divide the coasts of thy land, which the Lord thy God giveth thee to inherit, into three parts, that every slayer may flee thither.
Deuteronomy 19:3, King James Version
In context
2 Thou shalt separate three cities for thee in the midst of thy land, which the Lord thy God giveth thee to possess it.
3 Thou shalt prepare thee a way, and divide the coasts of thy land, which the Lord thy God giveth thee to inherit, into three parts, that every slayer may flee thither.
4 And this is the case of the slayer, which shall flee thither, that he may live: Whoso killeth his neighbour ignorantly, whom he hated not in time past;