A prophecy of redemption promises Jerusalem a total transformation in how the world perceives her. Following a long period of struggle, she will achieve universal recognition for her righteousness and undergo a profound change in status, symbolized by a new identity granted directly by God.
Following the final redemption, the nations of the world will witness the justice and kindness God performs for Jerusalem [רד״ק, מצודת דוד]. Commentators note a distinction in how different groups will perceive this transformation. According to [המלבי״ם], there is a hierarchy of understanding. The general nations will recognize the righteousness of the people and the truth of their teachings. The kings, possessing greater wisdom, will achieve a deeper realization, recognizing that the glory of the people far surpasses their own royal honor. Offering a different perspective, [אהבת יהונתן] suggests that the nations will observe the outward acts of justice and the fulfillment of commandments. The kings, however, will come closer to the sacred, allowing them to witness a deeper glory compared to inner, holy garments.
As a result of this global recognition, the city will receive a new name. [אהבת יהונתן] explains that this new identity signifies a time when the entire nation will be righteous and resemble their Creator. They will be known as children of the living God in a future era where the urge to do evil is completely abolished.
To give this new identity absolute authority, it will be declared directly by God. The primary approach among commentators is that God will explicitly specify and explain this name [רש״י, רד״ק, מצודת ציון, אבן עזרא, ביאור שטיינזלץ]. This new title is not left as a mystery; as the prophecy continues, the names are revealed to mean "My delight is in her" and "Sought out" [מצודת דוד, רד״ק, מלבי״ם, שד״ל]. God will not only declare the name but will also explain its meaning, showing His deep desire for His people [המלבי״ם]. The profound nature of this name relies entirely on its divine source. As [שד״ל] points out, if people were to call the city "My delight is in her" simply because her historical fortunes had improved, it would not carry true glory. The greatness of the name stems from the fact that it comes directly from the mouth of God. By using a possessive term, it is as if God Himself is stepping forward to personally testify to His enduring love for Jerusalem.