| Barnes' Notes on the Bible Servants to Hadarezer - This gives us an idea of the great power of Hadarezer, and consequently of the strength of Israel in David's victorious reign.
Clarke's Commentary on the BibleMade peace with Israel - They made this peace separately, and were obliged to pay tribute to the Israelites. Some copies of the Vulgate add here after the word Israel, Expaverunt et fugerunt quinquaginta et octo millia coram Israel; "and they were panic-struck, and fled fifty-eight thousand of them before Israel." This reading is nowhere else to be found. "Thus," observes Dr. Delaney, "the arms of David were blessed; and God accomplished the promises which he had made to Abraham, Genesis 15:18, and renewed to Joshua, Joshua 1:2, Joshua 1:4." And thus, in the space of nineteen or twenty years, David had the good fortune to finish gloriously eight wars, all righteously undertaken, and all honourably terminated; viz. 1. The civil war with Ish-bosheth. 2. The war against the Jebusites. 3. The war against the Philistines and their allies. 4. The war against the Philistines alone. 5. The war against the Moabites. 6. The war against Hadadezer. 7. The war against the Idumeans. 8. The war against the Ammonites and Syrians. This last victory was soon followed by the complete conquest of the kingdom of the Ammonites, abandoned by their allies. What glory to the monarch of Israel, had not the splendor of this illustrious epoch been obscured by a complication of crimes, of which one could never have even suspected him capable! We have now done with the first part of this book, in which we find David great, glorious, and pious: we come to the second part, in which we shall have the pain to observe him fallen from God, and his horn defiled in the dust by crimes of the most flagitious nature. Let him that most assuredly standeth take heed lest he fall.
Gill's Exposition of the Entire BibleAnd when all the kings that were servants to Hadarezer,.... That were subject to him, and at his beck and command, at least were hired by him into his service: saw that they were smitten before Israel; could not stand their ground against them, being too powerful for them: they made peace with Israel, and served them; became tributaries to them, whereby the promise of the land of Canaan made to Abraham and his seed, as reaching to the river Euphrates, had its accomplishment, Genesis 15:18, so the Syrians feared to help the children of Ammon any more; who standing by themselves, they were soon and easily conquered by David's forces, as recorded in the following chapters.
Keil and Delitzsch Biblical Commentary on the Old Testament"And when all the kings, the vassals of Hadarezer, saw that they were smitten before Israel, they made peace with Israel, and became subject to them; and Aram was afraid to render any further help to the Ammonites." It might appear from the first half of this verse, that it was only the vassals of Hadarezer who made peace with Israel, and became subject to it, and that Hadarezer himself did not. But the last clause, "and the Aramaeans were afraid," etc., shows very clearly that Hadarezer also made peace with the Israelites, and submitted to their rule; so that the expression in the first half of the verse is not a very exact one.
Geneva Study BibleAnd when all the kings that were servants to Hadarezer saw that they were smitten before Israel, they made peace with Israel, and served them. So the Syrians feared to help the children of Ammon any more.
Wesley's Notes 10:19 And served them - And thus at length was fulfilled the promise made to Abraham, and repeated to Joshua, that the borders of Israel should extend as far as the river Euphrates. The son of David sent his ambassadors, his apostles and ministers, to the Jewish church and nation. But they intreated them shamefully, as Hanun did David's, mocked them, abused them, slew them. And this it was that filled the measure of their iniquity, and brought upon them ruin without remedy.
Matthew Henry's Concise Commentary10:15-19 Here is a new attempt of the Syrians. Even the baffled cause will make head as long as there is any life in it; the enemies of the Son of David do so. But now the promise made to Abraham, Ge 15:18, and repeated to Joshua, Jos 1:4, that the borders of Israel should extend to the river Euphrates, was performed. Learn hence, that it is dangerous to help those who have God against them; for when they fall, their helpers will fall with them.
Matthew Henry's Whole Bible CommentaryVerses 15-19 Here is, 1. A new attempt of the Syrians to recover their lost honour and to check the progress of David's victorious arms. The forces that were lately dispersed rallied again, and gathered themselves together, v. 15. Even the baffled cause will make head as long as there is any life in it; the enemies of the Son of David do so, Matt, 22:34; Rev. 19:19. These, being conscious of their insufficiency, called in the aid of their allies and dependencies on the other side of the river (v. 16), and, being thus recruited, they hoped to make their part good against Israel, but they knew not the thoughts of the Lord, for he gathered them as sheaves into the floor; see Mic. 4:11-13. 2. The defeat of this attempt by the vigilance and valour of David, who, upon notice of their design, resolved not to stay till they attacked him, but went in person at the head of his army over Jordan (v. 17), and, in a pitched battle, routed the Syrians (v. 18), slew 7000 men, who belonged to 700 chariots, and 40,000 other soldiers, horse and foot, as appears by comparing 1 Chr. 19:18. Their general was killed in the battle, and David came home in triumph, no doubt. 3. The consequence of this victory over the Syrians. (1.) David gained several tributaries, v. 19. The kings, or petty princes, that had been subject to Hadarezer, when they saw how powerful David was, very wisely made peace with Israel, whom they found they could not make war with, and served them, since they were able to give them protection. Thus the promise made to Abraham (Gen. 15:18), and repeated to Joshua (ch. 1:4), that the borders of Israel should extend to the river Euphrates, was performed, at length. (2.) The Ammonites lost their old allies: The Syrians feared to help the children of Ammon, not because they had an unrighteous cause (justifying a crime which was a breach of the law of nations), but because they found it was an unsuccessful cause. It is dangerous helping those that have God against them; for, when they fall, their helpers will fall with them. Jesus Christ, the Son of David, sent his ambassadors, his apostles and ministers, after all his servants the prophets, to the Jewish church and nation; but they treated them shamefully, as Hanun did David's ambassadors, mocked them, abused them, slew them; and it was this that filled the measure of their iniquity, and brought upon them ruin without remedy (Mt. 21:35, 41, 22:7; compare 2 Chr. 26:16); for Christ takes the affronts and injuries done to his ministers as done to himself and will avenge them accordingly. | 
