Charles Ellicott Commentary 2 Chronicles 8:4

"And he built Tadmor in the wilderness, and all the store-cities, which he built in Hamath." — 2 Chronicles 8:4 (ASV)

And he built Tadmor in the wilderness. —That is, Palmyra, in the wilderness, on the traders’ route between the coast and Thapsacus on the Euphrates. See 1 Kings 9:18, where Tamar or Tammor of the Hebrew text is explained by the margin to mean Tadmor; and the epithet, “in the wilderness,” seems certainly to identify the two names. That Solomon was the founder of Palmyra is the tradition of the country to this day.

And all the store cities, which he built in Hamath. —1 Kings 9:19 mentions these cities, but not their locality. They were no doubt military strongholds, and served as outposts against the hostile neighboring kingdom of Zobah-Damascus. (See 1 Kings 11:23–25.) So far as they lay on the caravan route, they would also serve as provisioning stations. (Compare 2 Chronicles 32:28.)