Why did Allah Almighty express "بلدة ميتًا" (a dead land) in Surat Qaf using both feminine and masculine forms, and not say "بلدًا ميتًا" (a dead land - masculine) or "بلدة ميتة" (a dead land - feminine)?

Al-Qurtubi mentioned in his Tafsir, concerning theusti, "that We may bring thereby a dead land to life," that Allah said "maytan" (dead, masculine) and did not say "maytatan" (dead, feminine) because "baldah" (town/land, feminine) and "balad" (country/land, masculine) have the same meaning. It was also said that He intended "place" by "balad".