Deuteronomy 19:1-3

ASV_Strongs(i)
  1 H3068 When Jehovah H430 thy God H3772 shall cut off H1471 the nations, H776 whose land H3068 Jehovah H430 thy God H5414 giveth H3423 thee, and thou succeedest H3427 them, and dwellest H5892 in their cities, H1004 and in their houses;
  2 H914 thou shalt set apart H7969 three H5892 cities H8432 for thee in the midst H776 of thy land, H3068 which Jehovah H430 thy God H5414 giveth H3423 thee to possess it.
  3 H3559 Thou shalt prepare H1870 thee the way, H1366 and divide the borders H776 of thy land, H3068 which Jehovah H430 thy God H5157 causeth thee to inherit, H8027 into three parts, H7523 that every manslayer H5127 may flee thither.