Isaiah 38

It took me about 4 minutes to read this passage. In verses 2 and 3 Hezekiah prays the prayer of a man who has just learned that he is dying. In three dozen words the king of Israel pours out his heart to the King of kings. God was moved in a unique way by the prayers of this man. Had God denied Hezekiah's plea then the next king of Judah would have been an older son of Hezekiah. What is it that God saw in the heart of Hezekiah that led him to reverse his edict about this king? Was it the humility he poured out in verses 9 through 20? What spark in Hezekiah's heart melted God's heart?
Stuart