Charles Ellicott Commentary 2 Samuel 8:5

"And when the Syrians of Damascus came to succor Hadadezer king of Zobah, David smote of the Syrians two and twenty thousand men." — 2 Samuel 8:5 (ASV)

Syrians of Damascus. —So called from their capital, this being the most powerful branch of the Syrian race.

Twenty-two thousand men. —Josephus (Antiquities 7.5.2) quotes from the historian Nicolaus a mention of the defeat of Hadad at this place by David.