What does Isaiah 16:14 mean?

But now the Lord says, 'In just three years—like a hired worker would count them—Moab's glory will be gone. There will be only a few survivors, and they'll be weak and powerless.' Isaiah 16:14 - Modern Text Bible

(God sets a specific time for Moab's downfall. The destruction will be swift and thorough, leaving only a small, broken remnant.)