Numbers 21:13; Numbers 22:36

13 From there they set out and camped on the other side of the Arnon, which is in the wilderness that extends from the border of the Amorites, for the mArnon is the border of Moab, between Moab and the Amorites.


36 When Balak heard that Balaam had come, he went out to meet him at the city of Moab, fon the border formed by the Arnon, at the extremity of the border.