Numbers 21:13-15

LITV(i) 13 From there they pulled up and camped beyond Arnon, which is in the wilderness that comes out of the border of the Amorite; for Arnon is the border of Moab, between Moab and the Amorite; 14 therefore, it is said in the Book of the Wars of Jehovah: Waheb in Suphah, the torrents of Arnon, 15 and the slope of the torrent-beds that turn down toward the site of Ar, and lean on the border of Moab.