Charles Ellicott Commentary 1 Kings 11:24

"And he gathered men unto him, and became captain over a troop, when David slew them [of Zobah]: and they went to Damascus, and dwelt therein, and reigned in Damascus." — 1 Kings 11:24 (ASV)

When David slew them of Zobah. —The account of this war is found in 2 Samuel 8:1–13. The kingdom of Zobah was evidently a powerful state at that time, at war with the Syrian kingdom of Hamath, but holding supremacy over the Syrians of Damascus, and the “Syrians beyond the river” Euphrates; and—as the record shows—accumulating vast treasures of gold, silver, and brass.

The establishment of Rezon (and Hadad?) at Damascus must have taken place later; for at the time we find that David “put governors in Damascus,” and reduced its inhabitants to a tributary condition. Possibly there may have been some rising early in the reign of Solomon; for in 2 Chronicles 8:3, we find that Solomon had to “go up against Hamath-zobah,” with which expedition the foundation of Tadmor seems to be connected. But it is probable that the establishment of an independent power in Damascus dated only from the later days of Solomon.