Joshua 13:8, 10, 24-28

Half the tribe of Manasseh and the tribes of Reuben and Gad had already received their grants of land on the east side of the Jordan, for Moses, the servant of the LORD, had previously assigned this land to them.

It also included all the towns of King Sihon of the Amorites, who had reigned in Heshbon, and extended as far as the borders of Ammon.

Moses had assigned the following area to the clans of the tribe of Gad. Their territory included Jazer, all the towns of Gilead, and half of the land of Ammon, as far as the town of Aroer just west of Rabbah. It extended from Heshbon to Ramath-mizpeh and Betonim, and from Mahanaim to the territory of Lo-debar. In the valley were Beth-haram, Beth-nimrah, Succoth, Zaphon, and the rest of the kingdom of King Sihon of Heshbon. The western boundary ran along the Jordan River, extended as far north as the tip of the Sea of Galilee, and then turned eastward. The towns and their surrounding villages in this area were given as a homeland to the clans of the tribe of Gad.