Commentary on the Bible, by Adam Clarke, [1831], at sacred-texts.com
Moses continues to relate how they compassed Mount Seir, Deu 2:1. And the commands they received not to meddle with the descendants of Esau, Deu 2:2-8; nor to distress the Moabites, Deu 2:9. Of the Emims, Deu 2:10, Deu 2:11; the Horims, Deu 2:12. Their passage of the brook Zered, Deu 2:13. The time they spent between Kadesh-barnea and Zered, Deu 2:14; during which all the men of war that came out of Egypt were consumed, Deu 2:15, Deu 2:16. The command not to distress the Ammonites, Deu 2:17-19. Of the Zamzummims, Deu 2:20, the Anakims, Deu 2:21, the Horims, Deu 2:22, the Avims and Caphtorims, all destroyed by the Ammonites, Deu 2:23. They are commanded to cross the river Arnon, and are promised the land of Sihon, king of the Amorites, Deu 2:24, Deu 2:25. Of the message sent to Sihon, to request a passage through his territories, Deu 2:26-29. His refusal, Deu 2:30.The consequent war, Deu 2:31, Deu 2:32. His total overthrow, Deu 2:33; and extermination of his people, Deu 2:34. The spoils that were taken, Deu 2:35. And his land possessed from Aroer to Arnon by the Israelites, Deu 2:36; who took care, according to the command of God, not to invade any part of the territories of the Ammonites, Deu 2:37.
Turn you northward - From Mount Seir, in order to get to Canaan. This was not the way they went before, viz., by Kadesh-barnea, but they were to proceed between Edom on the one hand, and Moab and Ammon on the other, so as to enter into Canaan through the land of the Amorites.
Meddle not with them - That is, the Edomites. See on Num 20:14-21 (note).
The Lord - hath blessed thee, etc. - God had given them much property, and therefore they had no need of plunder; they had gold and silver to buy the provender they needed, and therefore God would not permit them to take any thing by violence.
The Emims dwelt therein - Calmet supposes that these people were destroyed in the war made against them by Chedorlaomer and his allies, Gen 14:5. Lot possessed their country after the destruction of Sodom and Gomorrah. They are generally esteemed as giants; probably they were a hardy, fierce, and terrible people, who lived, like the wandering Arabs, on the plunder of others. This was sufficient to gain them the appellation of giants, or men of prodigious stature. See next verse, Deu 2:11 (note).
Which also were accounted giants - This is not a fortunate version. The word is not giants, but רפאים Rephaim, the name of a people. It appears that the Emim, the Anakim, and the Rephaim, were probably the same people, called by different names in the different countries where they dwelt; for they appear originally to have been a kind of wandering free-booters, who lived by plunder. (See on Deu 2:10 (note)). It must be granted, however, that there were several men of this race of extraordinary stature. And hence all gigantic men have been called Rephaim. (See on Gen 6:4 (note), and Gen 14:5 (note)). But we well know that fear and public report have often added whole cubits to men's height. It was under this influence that the spies acted, when they brought the disheartening report mentioned Num 13:33.
The Horims also dwelt in Seir - The whole of this verse was probably added by Joshua or Ezra.
That also was accounted a land of giants - That was accounted the land or territory of the Rephaim.
Zamzummims - Supposed to be the same as the Zuzim, Gen 14:5. Of these ancient people we know very little; they were probably inconsiderable tribes or clans, "pursuing and pursued, each other's prey," till at length a stronger totally destroyed or subdued them, and their name became either extinct or absorbed in that of their conquerors. From the 10th to the 12th, and from the 20th to the 23d verse inclusive (Deu 2:10-12, Deu 2:20-23), we have certain historical remarks introduced which do not seem to have been made by Moses, but rather by Joshua or Ezra. By the introduction of these verses the thread of the narrative suffers considerable interruption. Dr. Kennicott considers both these passages to be interpolations. That they could not have made a part of the speech of Moses originally, needs little proof.
As the children of Esau which dwell in Seir - See the note on Num 20:21.
The Lord - hardened his spirit - See the notes on Exo 4:21, and Exo 9:15 (note), etc.
From Aroer - by the brink of the river of Arnon - See on Num 21:13 (note), etc.
Only unto the land of the children of Ammon thou camest not - God gave them their commission; and those only were to be cut off, the cup of whose iniquity was full. Though the Moabites and Ammonites were thus spared, they requited good with evil, for they fought against the Israelites, and cast them out of their possessions, Jdg 11:4, Jdg 11:5; Ch2 20:1, etc., and committed the most shocking cruelties; see Amo 1:13. Hence God enacted a law, that none of these people should enter into the congregation of the Lord even to their tenth generation: see Deu 23:3-6.