יחזקאל, פרק מ״ז, פסוק י״א

The prophetic vision of the river flowing from the Temple features miraculous waters that heal and sweeten the salty sea. However, this sweeping transformation has specific, deliberate exceptions. Certain bodies of water located near the sea, such as swamps and muddy marshes [רש"י, מלבי"ם, מצודות], along with various natural or artificial pits and depressions where water collects [רש"י, מצודת ציון, רד"ק, שטיינזלץ], will not be sweetened. Instead, they will retain their original saltiness [רש"י, שטיינזלץ]. The reason for this is entirely natural. The fresh, sweet waters of the new river simply will not reach these isolated pockets [מלבי"ם].

Leaving these areas untouched is not a curse or a flaw in the miracle, but rather a practical necessity for human benefit. These designated areas will continue to serve their traditional purpose of producing salt, which is essential for flavoring food and preserving goods [מצודת דוד, רד"ק, שטיינזלץ]. These specific locations will effectively function as actual salt mines [רד"ק].

Beyond the physical landscape, this separation carries a deeper allegorical meaning. The stagnant, disconnected marshes that remain unhealed represent wild and ignorant individuals who isolate themselves from the flowing river of wisdom and knowledge. Just as these cut-off swamps eventually dry up and leave behind nothing but barren salt, such people will not endure. They will ultimately vanish like smoke and turn into mere pillars of salt [מלבי"ם].