Numbers 21:13

13 which they left, and setted tents against (the) Arnon, which is in the desert, and it appeareth in the coasts of Amorites. Forsooth (the) Arnon is the term of Moab, and parteth Moabites and Amorites. (and they left there, and pitched their tents on the north side of the Arnon River, which is in the wilderness, that goeth into the land of the Amorites. The Arnon River is the border of Moab, and it separateth the Moabites 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 from whence they went forth, and setted tents in Iyeabarim, in the wilderness that beholdeth Moab, against the east coast. (and they went forth from there, and pitched their tents in Iyeabarim, in the wilderness on Moab's eastern border.)

12 And they moved from thence, and came to the strand of Zared; (And they went from there, and came to the valley of the Zared River;)

13 which they left, and setted tents against (the) Arnon, which is in the desert, and it appeareth in the coasts of Amorites. Forsooth (the) Arnon is the term of Moab, and parteth Moabites and Amorites. (and they left there, and pitched their tents on the north side of the Arnon River, which is in the wilderness, that goeth into the land of the Amorites. The Arnon River is the border of Moab, and it separateth the Moabites and the Amorites.)

14 Wherefore it is said in the book of battles of the Lord, As he did in the Red Sea, so he shall do in the strands of (the) Arnon; (And so it is said in the Book of the Battles of the Lord, As he did at the Red Sea, so he also did at the Arnon River,)

15 the hard rocks of the strands were bowed down, that they shall rest in Ar, or abide there, and should lie in the coasts of Moabites. (and from the cliffs of the river, down to the city of Ar, that sitteth on the border of Moab.)