After enduring a long period of crisis and looming threats, the inhabitants of Jerusalem step into a new reality of complete physical and spiritual healing. This profound recovery is deeply tied to a monumental salvation and the total forgiveness of their past wrongdoings.
The primary approach among commentators is that the residents of the city will no longer complain of illness or the lingering pain of their past hardships [אבן עזרא, רד״ק, מצודת דוד, ביאור שטיינזלץ, מצודת ציון]. This dramatic shift occurs because the people are granted absolute forgiveness for their sins, which naturally strips away all their physical weaknesses, diseases, and afflictions. According to [רד״ק], this state of atonement was earned through the efforts of King Hezekiah, who corrected the people and guided them back to proper behavior, ultimately bringing about salvation from God. In this renewed state, the people of Jerusalem will no longer feel powerless or incapable of standing up to the terrifying threat of the Assyrian army [מלבי״ם].
A different perspective connects this newfound vitality to the aftermath of battle, specifically the gathering of spoils from the defeated enemy [שד״ל, אברבנאל]. In this view, even a person who is resting or confined to a sickbed will not use their illness as an excuse to stay behind [שד״ל]. Instead, they will be filled with sudden strength and rise to collect the wealth left by the enemy. Furthermore, taking these massive spoils will not be counted against them as a wrongdoing, which is why they are described as a people whose sins are lifted [אברבנאל].
Offering a unique interpretation, [רש״י] suggests that the focus is not on the Israelites themselves, but on the surrounding nations. These neighboring countries will stop complaining that they suffer misfortune simply by being close to the people of Israel, because the Israelites have now been forgiven by God and are no longer drawing divine punishment.
Ultimately, the prophecy paints a picture of a nation entirely free from harm, protected and cleansed of all past faults [שד״ל]. While this vision is widely understood to have taken place during the historical conflict between King Hezekiah and Sennacherib, some viewpoints suggest it points toward a future time, such as the Messianic era or the final great wars [רד״ק, אברבנאל]. Additionally, this promise serves as the foundation for the broader concept that anyone who chooses to live in the Land of Israel is granted forgiveness for their sins [אברבנאל].