So the servants of king Hezekiah came to Isaiah. And Isaiah said unto them, Thus shall ye say unto your master, Thus saith the LORD, Be not afraid of the words that thou hast heard, wherewith the servants of the king of Assyria have blasphemed me. 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.
The LORD assured Hezekiah, through Isaiah, that there was no reason to fear the king of Assyria. The Lord would send a spirit upon Sennacherib so that, hearing a rumor, he would return to his own land and be killed there.