Charles Ellicott Commentary 2 Chronicles 26:6

"And he went forth and warred against the Philistines, and brake down the wall of Gath, and the wall of Jabneh, and the wall of Ashdod; and he built cities in [the country of] Ashdod, and among the Philistines." — 2 Chronicles 26:6 (ASV)

And he went forth and warred against the Philistines. —At the outset of his reign this able prince had given promise of his future by seizing and fortifying the port of Elath, and thus probably completing the subjugation of Edom, which his father had more than begun. Afterwards he assumed the offensive against the Philistines, Arabs, and Maonites, who had invaded the country under his predecessors (2 Chronicles 21:16; 2 Chronicles 20:1).

Brake down the wall of Gath. —After taking the city. (As to Gath, see 1 Chronicles 18:1; 2 Chronicles 11:8.)

Jabneh. —The Jamnia of Maccabees and Josephus; now the village of Jebnah, about twelve miles south of Joppa (the same as Jabneel, Joshua 15:11).

Ashdod. — Esdûd. (Compare to Joshua 13:3.) Like Gath, one of the five sovereign states of the Philistines. It commanded the great road to Egypt; therefore its possession was of first-rate importance to the contending military powers of Egypt and Assyria. Sargon captured it 719 B.C. (Compare to Isaiah 20:1.)

About Ashdod. — In Ashdod, i.e., in the canton of that name.

And among the Philistines. —That is, elsewhere in their territory. Uzziah appears to have reduced the Philistines to a state of complete vassalage. They were not, however, annexed to Judah, but ruled by their own kings.