Thus saith Hezekiah:
"This is a day of trouble and of discipline and of contumely. It may be God, thy God, will hear all the words of the high official, whom his master, the King of Assyria, has sent to defy the living God, and will rebuke the words which the Lord your God has heard; therefore lift up your prayer for the remnant that is left."
When Isaiah heard the message of the king, he sent back this reply of hope and courage to the palace:
"Thus saith the Lord: 'Be not afraid of the words that thou hast heard, with which the servants of the King of Assyria have blasphemed me. Behold I will put forth a spirit in him so that he shall hear tidings and shall return to his own land, and I will cause him to fall by the sword in his own land.'"
Hezekiah, acting upon the advice of Isaiah, then sent Sennacherib's emissaries back to Lachish with a flat refusal to do what the King had asked him.
When the Commander-in-Chief returned to Lachish, to his great amazement, Sennacherib and his army were not there. An officer who was left behind, however, told him that Sennacherib had broken camp and had marched against Libnah.
The next that was heard of the Assyrian armies in Jerusalem was that a plague had fallen upon the camp of Sennacherib and that, in great disgust and disappointment, the king and what remained of his forces, had returned to Nineveh.
It was at that time that Isaiah gave expression to a conception of God's relationship to the nations of the earth that was entirely different from that held by the people up to this time.
According to Isaiah, God had used Assyria as a rod with which to whip the people of Judah, God's chosen people, into an understanding of His law and commandments, by which they should live.
Now that Hezekiah and his people had thoroughly reformed and were following in the ways of God and His commandments, Assyria's work was done. Because Assyria, however, had prided herself that she had become a great power in the world on account of her own strength, God would now destroy Assyria.