2 Samuel 10:18
And the Syrians fled before Israel; and David slew the men of seven hundred chariots of the Syrians, and forty thousand horsemen, and smote Shobach the captain of their host, who died there. And the Syrians fled before Israel; and David slew the men of seven hundred chariots of the Syrians, and forty thousand horsemen, and smote Shobach the captain of their host, who died there.
The rout of the Syrians was among the greatest wars and victories of David's reign and brought some of the most extensive additions to his power. The vast coalition of surrounding nations that rose against Israel sprang from jealousy of his increasing power and was wholly unprovoked by him. The crisis began when David sent ambassadors in sympathy to Hanun son of Nahash to return the kindness Nahash had shown him, and Hanun on the advice of his counselors treated them as spies and subjected them to scorn and insult. The Ammonites hated the true God and were bitter enemies of Israel, and being unable to grasp a generous spirit, their envy and suspicion misread good intentions, as happens when Satan controls minds. Knowing that insulting ambassadors demanded retaliation, the Ammonites hired chariots and horsemen from Mesopotamia and Syria-maachah and Zobah and joined with the peoples between the Euphrates and the Mediterranean to surround the north and east of Canaan and crush Israel.
The war unfolded in two stages, and in the first Israel did not wait to be invaded but crossed the Jordan under Joab toward the Ammonite capital, where after Joab urged the troops to be courageous for their people and the cities of God and to leave the result to the Lord, the united allies were defeated. This verse belongs to the second stage the next year, when Syria renewed the war with an immense army and David took the field in person and by God's blessing inflicted so disastrous a defeat that the Syrians from Lebanon to the Euphrates abandoned the war and became tributary to Israel. The war against the Ammonites was then pressed until their strongholds fell and the whole region came under Israel's dominion.