Deuteronomy 4:45

that the man slayer might flee there, who kills his neighbor unintentionally and didn’t hate him in time past, and that fleeing to one of these cities he might live:

Bezer in the wilderness, in the plain country, for the Reubenites; and Ramoth in Gilead for the Gadites; and Golan in Bashan for the Manassites.

This is the law which Moses set before the children of Israel.

beyond the Jordan, in the valley opposite Beth Peor, in the land of Sihon king of the Amorites, who lived at Heshbon, whom Moses and the children of Israel struck when they came out of Egypt.

They took possession of his land and the land of Og king of Bashan, the two kings of the Amorites, who were beyond the Jordan toward the sunrise;

from Aroer, which is on the edge of the valley of the Arnon, even to Mount Siyon (also called Hermon),