Numbers 21:13
21:13 From there they moved on and camped on the other side of the Arnon, in the wilderness that extends from the regions 1 of the Amorites, for Arnon is the border of Moab, between Moab and the Amorites.
Numbers 22:3
22:3 And the Moabites were greatly afraid of the people, because they were so numerous. The Moabites were sick with fear because of the Israelites.