Isaiah 37:7
Behold, I will send a blast upon him, and he shall hear a rumour, and return to his own land; and I will cause him to fall by the sword in his own land. Behold, I will send a blast upon him, and he shall hear a rumour, and return to his own land; and I will cause him to fall by the sword in his own land.
This was God's message to Hezekiah through the prophet when the king of Assyria came up and threatened Judah, belonging to the history of Hezekiah and to the record of Sennacherib's campaign against Judah. That campaign came from the southwest, and is distinguished from the campaign described in Isaiah 10 as coming from the northeast. The chapter stands in parallel to 2 Kings 19 with considerable verbal difference between the two accounts. It stands in Isaiah 36-39, which gives mighty lessons against trusting in men and vividly portrays man's frailties, seen even in Hezekiah who failed to give God the glory for his healing and instead showed his gathered earthly riches to the Babylonian ambassadors who afterward despoiled the kingdom.
The word blast means a breath or blowing of air, the Hebrew word being able to describe a moving breath or wind. After Sennacherib had taken forty-six cities of Judah and stood before Lachish, he sent messengers and insulting letters that taunted Hezekiah and likened Jehovah to the gods of the nations made by men's hands, in blasphemy against God's name and cause. The promise was given in response to Hezekiah's humility and to the prayer of Hezekiah and Isaiah, after Hezekiah brought the insulting letter before the Lord when the enemy seemed overwhelming and taunted him. In the verse God promises to send a blast upon the Assyrian king, so that he will hear a report or rumour, return to his own land, and fall or die there by the sword.
The assurance was fulfilled when God sent an angel who in one night cut off all the mighty men of valor and leaders and captains in the Assyrian camp, slaying 185,000 men while the army was at Libnah with the king. So Sennacherib returned with shame of face to his own land, and when he came into the house of his god those who came from his own bowels slew him there with the sword, and thus Jehovah saved Hezekiah and Jerusalem and guided them on every side. The verse shows that God could deliver Hezekiah and Israel from a powerful army even when they were outnumbered, so that the Assyrian threat did not make God's people powerless. It promises the Lord's wonderful deliverance from the power of Assyria by His angel, and by the slaughter of Sennacherib's host bears witness to corrupt and far-departed Assyria that He is God above all, by revelation and living testimony and not only by rain and fruitful seasons.
Considered alongside the accounts in Kings and Chronicles, this history of the king returning to his own land and dying there does not support identifying the Tophet of Isaiah 30:33 with the destruction of the Assyrian army. The assurance that a disturbing report would make the enemy king return to his own land, where he would die by the sword for defying God, is held by some to be fulfilled when Rabshakeh is turned back and later pays with his life.