Numbers 21:13

13 From there they set out, and encamped on the other side of the Arnon, which is in the wilderness, that extends from the boundary of the Amorites; for the Arnon is the boundary of Moab, between Moab and the Amorites.

Numbers 21:13 Meaning and Commentary

Numbers 21:13

From thence they removed, and pitched on the other side of
Arnon
A river on the borders of Moab:

which is in the wilderness that cometh out of the coasts of the
Amorites;
according to Jarchi, they went round the land of Moab, all to the south and east, and came not into the border of Moab, as Jephthah said, ( Judges 11:18 ) but before they came hither they had a station at Almondiblathaim, ( Numbers 33:46 Numbers 33:47 )

for Arnon is the border of Moab, between Moab and the Amorites;
a river which divided these two countries, and bounded them; and Moses is the more particular in this account, to show that the Israelites took nothing from the Moabites, but what the Amorites had taken from them, they being charged not to distress the Moabites and Ammonites, ( Deuteronomy 2:9 Deuteronomy 2:19 ) , see Jephthah's defence, ( Judges 11:15-27 ) .

Numbers 21:13 In-Context

11 And they set out from Oboth, and encamped at I'ye-ab'arim, in the wilderness which is opposite Moab, toward the sunrise.
12 From there they set out, and encamped in the Valley of Zered.
13 From there they set out, and encamped on the other side of the Arnon, which is in the wilderness, that extends from the boundary of the Amorites; for the Arnon is the boundary of Moab, between Moab and the Amorites.
14 Wherefore it is said in the Book of the Wars of the LORD, "Waheb in Suphah, and the valleys of the Arnon,
15 and the slope of the valleys that extends to the seat of Ar, and leans to the border of Moab."
Revised Standard Version of the Bible, copyright 1952 [2nd edition, 1971] by the Division of Christian Education of the National Council of the Churches of Christ in the United States of America. Used by permission. All rights reserved.