If the mighty army of the great Assyrian king were successfully defied by a petty monarch like Hezekiah, it would force the surrounding nations to confess that the escape was owing to the protecting hand of Yahweh. They would thus be taught, in spite of themselves, that He, and He alone, was the true God.
Related Commentaries of 2 Kings 19:19
2 Kings 19:19
19 Now therefore, O LORD our God, I beseech thee, save thou us out of his hand, that all the kingdoms of the earth may know that thou art the LORD God, even thou only.