We now come to the second part of the song, where the complete unexpectedness of Jerusalem’s terrible fate is highlighted. In this verse, we are reminded of the reputation that Jerusalem had among the nations. It was seen as an unconquerable city. Jerusalem lay on Mount Zion, which made it so well-protected that the Jebusites (its original inhabitants) had bragged that a few lame and blind men would be enough to protect their city against David (2 Samuel 5:6). David and his successors later fortified the city even more.
But most of all, Jerusalem was the city of the Lord, the Great King who was its protector (Psalm 48:1–14). Sennacherib, the king of the Assyrians, could therefore not conquer this city, even though he conquered every other city of the nations (2 Kings 19:35–37). Events such as this one gave to Jerusalem its great name. The Judeans themselves started to believe that their city was invincible (Jeremiah 7:4; Jeremiah 26:11). But when the Lord left the city, the unthinkable happened and it fell.
12 The kings of the earth did not believe, nor any of the inhabitants of the world, that foe or enemy could enter the gates of Jerusalem.