ירמיהו, פרק ל״ד, פסוק ז׳

A relentless military campaign is underway as the Babylonian army sweeps through the land, attacking Jerusalem and the final strongholds of Judah. The invading forces focus their assault on the last few cities that the king of Babylon has not yet managed to conquer [מצודת דוד].

Specifically, the battle rages against Lachish and Azekah. These two locations are the only ones left standing from all the cities of Judah [ביאור שטיינזלץ]. They remain as the final pockets of resistance because the Babylonian forces have already systematically captured every other city in the region, completely destroying their fortresses in the process [מצודת דוד].