John Gill's Bible Commentary Ver. 9. And the Lord said unto me , etc.] When upon the borders of Moab: distress not the Moabites, neither contend with than in battle ; besiege not any of their cities, nor draw them into a battle, or provoke them to fight: for I will not give thee of their land for a possession ; at least not as yet, the measure of their sins not being fully up, and the time of their punishment not come; otherwise in David’s time they were subdued, and became tributaries to him, and the Edomites also, ( 2 Samuel 8:2,14), because I have given Ar unto the children of Lot for a possession ; so the Moabites were, they sprung from Moab, a son of Lot by his firstborn daughter, ( Genesis 19:37). Ar was the metropolis of Moab, called Ar of Moab, ( Isaiah 15:1) and is here put for the whole country of Moab; so Aben Ezra interprets it of Moab. Jarchi says it is the name of the province; in the Septuagint version it called Aroer.
Matthew Henry Commentary
Verses 8-23 - We have the origin of the Moabites, Edomites, and Ammonites. Moses als gives an instance older than any of these; the Caphtorims drove the Avims out of their country. These revolutions show what uncertai things wordly possessions are. It was so of old, and ever will be so Families decline, and from them estates are transferred to familie that increase; so little continuance is there in these things. This i recorded to encourage the children of Israel. If the providence of God has done this for Moabites and Ammonites, much more would his promis do it for Israel, his peculiar people. Cautions are given not to meddl with Moabites and Ammonites. Even wicked men must not be wronged. God gives and preserves outward blessings to wicked men; these are not the best things, he has better in store for his own children.
Original Hebrew ויאמר559 יהוה3068 אלי413 אל408 תצר6696 את853 מואב4124 ואל408 תתגר1624 בם מלחמה4421 כי3588 לא3808 אתן5414 לך מארצו776 ירשׁה3425 כי3588 לבני1121 לוט3876 נתתי5414 את853 ער6144 ירשׁה׃3425