Deuteronomy 4:40-49

40 Obey his laws and commands which I'm giving you today. Then things will go well for you and your descendants. You will live for a long time in the land. The LORD your God is giving you the land for as long as you live.
41 Then Moses set aside three cities on the east side of the Jordan River.
42 Those who unintentionally killed someone whom they had never hated could flee to one of these cities and save their lives.
43 The cities were Bezer on the desert plateau for the tribe of Reuben, Ramoth in Gilead for the tribe of Gad, and Golan in Bashan for the tribe of Manasseh.
44 This is what Moses taught the people of Israel.
45 These are the commandments, laws, and rules Moses gave the Israelites after they had left Egypt.
46 He gave these to the people when they were east of the Jordan River in the valley near Beth Peor, in the land of King Sihon of the Amorites, who ruled in Heshbon. Moses and Israel defeated him after they left Egypt.
47 They took possession of his land and the land of King Og of Bashan, the two kings of the Amorites who were east of the Jordan River.
48 This land went from Aroer on the edge of the Arnon Valley to Mount Siyon (that is, Mount Hermon).
49 It included all the plains on the east side of the Jordan River as far as the Dead Sea at the foot of the slopes of Mount Pisgah.