Numbers 21:13

21:13 From there they traveled, and encamped on the other side of the Arnon, which is in the wilderness, that comes out of the border of the Amorites: for the Arnon is the border of Moab, between Moab and the Amorites.
-World English Bible

Other Translation

21:13 From thence they removed, and pitched on the other side of Arnon, which [is] in the wilderness that cometh out of the coasts of the Amorites: for Arnon [is] the border of Moab, between Moab and the Amorites.
-King James Version