2 Samuel 10:9
When Joab saw that the front of the battle was against him before and behind, he chose of all the choice men of Israel, and put them in array against the Syrians: When Joab saw that the front of the battle was against him before and behind, he chose of all the choice men of Israel, and put them in array against the Syrians:
This moment belongs to the greatest wars and victories of David's reign, which brought the most extensive additions to his power. The battle arose from a vast coalition of the surrounding nations against his kingdom that was wholly unprovoked by him and sprang from jealousy of his increasing power. After ambassadors sent with kindness to Hanun son of Nahash were scorned and insulted as spies, the Ammonites made themselves odious to David. The Ammonites hired chariots and horsemen from Mesopotamia and from Syria-maachah and from Zobah, thirty-two thousand chariots, and gathered with allies from the region between the Euphrates and the Mediterranean Sea, so that the north and east of Canaan was encircled with armed foes banded together to crush Israel, placing the front of the battle against Joab before and behind.
The verse shows Israel under Joab taking the offensive across the Jordan toward the Ammonite capital instead of waiting to be invaded. Faced with allied Ammonite and Syrian forces, Joab put his choice men in array against the Syrians and urged his army to behave valiantly for their people and for the cities of God and to leave the outcome to the Lord doing what is good in His sight. By God's blessing the united allies were overcome in the first battle. When the Syrians renewed the war the next year with an immense army, David took the field in person and defeated them so disastrously that the Syrians from Lebanon to the Euphrates gave up the war and became tributary to Israel, while David pushed the war against the Ammonites with vigor until their strongholds fell and the whole region came under Israel's dominion.