Deuteronomy 4:41-43

41Then Moses set apart three cities beyond the Jordan, toward the east.

42There the manslayer might flee, who kills his neighbor unintentionally and did not hate him previously. He may flee to one of these cities and live:

43Bezer in the wilderness on the plateau for the Reubenites, Ramot in the Gilead for the Gadites, and Golan in the Bashan for the Manassites.