Their border was: Jazer and all the cities of Gilead, and half the land of the children of Ammon to Aroer that is before Rabbah, Bible see other translations

“Aroer.” This is a different Aroer from the one mentioned that is on the southern side of Reuben’s territory (Josh. 12:2; 13:16; Deut. 2:36). Aroer is the name of a plant that grows in the desert, and so a few different arid towns were named “Aroer.”

“that is before Rabbah.” From Gad’s perspective, Rabbah is east of Gad’s eastern border. The Israelites were told they could not have the territory of Moab or Ammon. The Ammonites would have normally taken the land west to the Jordan River, but the Amorites kept them to the east.

Commentary for: Joshua 13:25