ירמיהו, פרק מ״ח, פסוק ח׳

The impending ruin of Moab is an inescapable and absolute catastrophe, leaving no avenue of escape for any region or settlement. An invader will systematically sweep through the nation, ensuring that not a single city survives the devastation [מצודת דוד, רד״ק, ביאור שטיינזלץ]. This ruin extends beyond the populated centers to strike the very geography of the land, specifically targeting the cities located in the deep valleys and those on the flat plains [מצודת דוד].

The nature of the devastation adapts directly to the specific landscape. A valley faces actual physical erasure, as it can be entirely filled with earth and rubble until it ceases to exist as a valley. A flat plain, however, cannot physically vanish. Instead, its destruction occurs through a complete loss of its natural qualities, transforming a once-fertile expanse into a barren, desolate wasteland [מלבי״ם].

This sweeping and total collapse is an absolute certainty because it is the direct result of a divine decree [רד״ק, ביאור שטיינזלץ]. Since God Himself has spoken and determined this fate, the destruction of the land is guaranteed to come to pass exactly as He declared [מצודת דוד].