Albert Barnes 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 - The Syrians (Aram), whose capital was Damascus, were the best known and most powerful. Damascus (written Darmesek in marginal references, according to the late Aramean orthography) is first mentioned in Genesis 15:2. According to Nicolaus of Damascus, cited by Josephus, the Syrian king’s name was Hadad.