A divine oath seals the absolute and irreversible fate of a major center of power, transforming it from a thriving capital into an eternal symbol of destruction. The impending collapse will leave no aspect of the city or its surroundings untouched, destined to become a historical wasteland.
The primary approach among commentators is that the targeted city is a great royal capital in Edom [רד״ק, מלבי״ם], often serving as a symbol for the entire Edomite nation [ביאור שטיינזלץ]. Others note that it was originally a fortified Moabite city, but it suffers this devastating blow alongside Edom due to its deep historical ties to the Edomite kings [רש״י, מצודת דוד]. Taking a more symbolic and far-reaching view, another perspective identifies the city with Rome, viewing it as the center of government and religion for the descendants of Edom during their exile [אברבנאל].
This catastrophic destiny is reserved for the End of Days. It represents a second and final destruction of Edom that will occur during the era of redemption. This downfall will take place as part of a massive global conflict among various nations, after which the city will remain in ruins forever [מצודת דוד, מלבי״ם, אברבנאל].
The unfolding disaster strikes the city in four distinct ways. First, it will be reduced to absolute emptiness and desolation [מצודת ציון, מצודת דוד], a state that will consume the entire surrounding region [מלבי״ם]. Second, the once-great city will become a focal point of intense shame and disgrace in the eyes of the world [מצודת דוד]. Third, it will face extreme ruin. This is understood either as severe drought and dryness [מצודת ציון, ביאור שטיינזלץ] or as a complete absence of anything good [מצודת דוד]. Some commentators draw a careful distinction here, noting that while the desolation affects the land itself, the ruin specifically targets the destruction of its buildings [מלבי״ם] or points to a state of general devastation [ביאור שטיינזלץ]. Finally, the city's fate will be so horrific that it will become a literal curse. People will use its name as a common expression, wishing that their enemies suffer the exact same doom [מצודת דוד]. This ultimate curse is considered an even harsher punishment than the public disgrace [מלבי״ם].
The destruction does not stop at the capital. Every town under its government and all the cities within the state will absorb a similar, crushing blow [מצודת דוד, מלבי״ם]. In a stark reversal of fortune, the more populated and flourishing a place once was, the greater and more dramatic its fall will be. These areas will be reduced to eternal ruins, places where no human being will ever live again [מלבי״ם, אברבנאל].