23 But Sihon wouldn't let Israel go through. Instead he got his army together and marched into the wilderness to fight Israel. At Jahaz he attacked Israel. 24 But Israel fought hard, beat him soundly, and took possession of his land from the Arnon all the way to the Jabbok right up to the Ammonite border. They stopped there because the Ammonite border was fortified. 25 Israel took and occupied all the Amorite cities, including Heshbon and all its surrounding villages. 26 Heshbon was the capital city of Sihon king of the Amorites. He had attacked the former king of Moab and captured all his land as far north as the river Arnon.
Matthew Henry's Commentary on Numbers 21:23-26
Commentary on Numbers 21:21-35
(Read Numbers 21:21-35)
Sihon went with his forces against Israel, out of his own borders, without provocation, and so ran upon his own ruin. The enemies of God's church often perish by the counsels they think most wisely taken. Og, king of Bashan, instead of being warned by the fate of his neighbours, to make peace with Israel, makes war with them, which proves in like manner his destruction. Wicked men do their utmost to secure themselves and their possessions against the judgments of God; but all in vain, when the day comes on which they must fall. God gave Israel success, while Moses was with them, that he might see the beginning of the glorious work, though he must not live to see it finished. This was, in comparison, but as the day of small things, yet it was an earnest of great things. We must prepare for fresh conflicts and enemies. We must make no peace or truce with the powers of darkness, nor even treat with them; nor should we expect any pause in our contest. But, trusting in God, and obeying his commands, we shall be more than conquerors over every enemy.