The sin committed by Hezekiah asleep, he had to atone for awake. If he refused to devote a song of praise to God for his escape from the Assyrian peril, he could not refrain from doing it after his recovery from the dangerous sickness that befell him. This sickness was a punishment for another sin beside ingratitude. He had "peeled off" the gold from the Temple, and sent it to the king of the Assyrians; therefore the disease that afflicted him caused his skin to "peel off."
Moreover, this malady of Hezekiah's was brought upon him by God, to afford an opportunity for the king and the prophet Isaiah to come close to each other. The two had had a dispute on a point of etiquette. The king adduced as a precedent the action of Elijah, who "went to show himself unto Ahab," and demanded that Isaiah, too, should appear before him. The prophet, on the other hand, modelled his conduct after Elisha's, who permitted the kings of Israel, and Judah, and Edom, to come to him.
But God settled the dispute by afflicting Hezekiah with sickness, and then He bade Isaiah go to the king and pay the visit due to the sick. The prophet did the bidding of God. When he appeared in the presence of the ailing king, he said: "Set thine house in order, for thou wilt die in this world and not live in the next" a fate which Hezekiah incurred because he had failed to take unto himself a wife and bring forth posterity.
The king's defense, that he had preferred a celibate's life because he had seen in the holy spirit that he was destined to have impious children, the prophet did not consider valid. He rebutted it with the words: "Why does thou concern thyself with the secrets of the All-Merciful? Thou hast but to do thy duty. God will do whatsoever it pleases Him."
Thereupon Hezekiah asked the daughter of the prophet in marriage, saying: "Perchance my merits joined to thine will cause my children to be virtuous." But Isaiah rejected the proposal of marriage, because he knew that the decree of God ordaining the king's death was unalterable. Whereupon the king: "Thou son of thus has it been transmitted to me from the house of my ancestor: Even if a sharp sword rests at the very throat of a man, he may yet not refrain from uttering a prayer for mercy."