“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.”
Numbers 21:13 (WEB)
Context Reading
11They traveled from Oboth, and encamped at Iyeabarim, in the wilderness which is before Moab, toward the sunrise. 12From there they traveled, and encamped in the valley of Zered. 13From 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. 14Therefore it is said in The Book of the Wars of Yahweh, “Vaheb in Suphah, the valleys of the Arnon, 15the slope of the valleys that incline toward the dwelling of Ar, leans on the border of Moab.”