Numbers 35:14

Then Moses severed three cities on this side Jordan toward the sunrising; That the slayer might flee thither, which should kill his neighbor unawares, and hated him not in times past; and that fleeing unto one of these cities he might live: Namely, Bezer in the wilderness, in the plain country, of the Reubenites; and Ramoth in Gilead, of the Gadites; and Golan in Bashan, of the Manassites.

And if the LORD thy God enlarge thy coast, as he hath sworn unto thy fathers, and give thee all the land which he promised to give unto thy fathers; If thou shalt keep all these commandments to do them, which I command thee this day, to love the LORD thy God, and to walk ever in his ways; then shalt thou add three cities more for thee, beside these three: That innocent blood be not shed in thy land, which the LORD thy God giveth thee for an inheritance, and so blood be upon thee.

And they appointed Kedesh in Galilee in mount Naphtali, and Shechem in mount Ephraim, and Kirjatharba, which is Hebron, in the mountain of Judah. And on the other side Jordan by Jericho eastward, they assigned Bezer in the wilderness upon the plain out of the tribe of Reuben, and Ramoth in Gilead out of the tribe of Gad, and Golan in Bashan out of the tribe of Manasseh. 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.