Sennacherib turned back 2KI 19:35

After Isaiah announced that the Assyrian would not even shoot an arrow into the city, the camp was struck that same night. Sennacherib broke off the siege and returned home to Nineveh instead of taking Jerusalem. There, some time later, his own sons killed him inside the house of his god.

The letter mocked the Lord directly by claiming no god had ever rescued anyone from Assyria's hand. Hezekiah spreads it out before the Lord as an act of prayer, laying the insult before God rather than answering it himself. It is a gesture of appeal, putting the matter into God's hands instead of relying on Judah's weakened defenses.

This is a common point of confusion, since Assyria had already taken every other fortified city of Judah. Jerusalem is the one city that does not fall: Isaiah's word is that the Assyrian will not shoot even a single arrow into it, and the camp is struck before any assault takes place. Sennacherib withdraws without ever breaching the city.

Christians read this moment in more than one way. Some take it as a direct, unexplained act of God striking the camp overnight, while others picture God working through a natural cause such as disease, with Scripture still crediting the outcome to the Lord. Either way, the text ties the event to Isaiah's earlier word that the Assyrian would fail to take the city.