Numbers 21:13 in the King James Version
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.
Context
12 From there they traveled, and encamped in the valley of Zered.
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.
14 Therefore it is said in The Book of the Wars of the LORD, “Vaheb in Suphah, the valleys of the Arnon,