God stopped Isaiah as he was leaving and told him to go back and tell Hezekiah that He had heard his prayer and seen his tears and He would heal him. When Hezekiah heard this he asked for a sign from the Lord that He would do what He said. So the Lord let the shadow go back ten degrees...meaning He put time back. The Lord added 15 years to Hezekiah’s life.
God honoured Hezekiah’s prayer and things changed for him. During the fifteen years that he had, Hezekiah had a son who later became king. If you want to, you can read on down through chapter two and see that Hezekiah’s son was one of the most wicked Kings that had ever come to power. Had Hezekiah known what his son would turn out like, I wonder if he would have asked that his life be extended? He might have been more than willing to die so that his people wouldn’t have been led into so much sin.
Be very careful what you pray for, because your prayer may be answered and you too may find yourself wishing you had never asked for what you got. When you are asking God for something, always ask Him what His will is. If you do that, you will never go wrong in your praying.