Joshua 20:9

These were the cities appointed for all the children of Israel, and for the stranger that sojourneth among them, that whosoever killeth any person at unawares might flee thither, and not die by the hand of the avenger of blood, until he stood before the congregation.

Cities. There were six; three on the west, and three on the east of Jordan. In the first instance they were a provision of the criminal law of the Hebrews, necessary in the circumstances of that people (see the note at Numbers 35:9; Deuteronomy 19:1); and at the same time they were designed also typically to point out the sinner's way to Christ (Hebrews 6:18).