Isaiah 38:5-7

Go, and say to Hezekiah, Thus saith the LORD, the God of David thy father, I have heard thy prayer, I have seen thy tears: behold, I will add unto thy days fifteen years. And I will deliver thee and this city out of the hand of the king of Assyria: and I will defend this city. And this shall be a sign unto thee from the LORD, that the LORD will do this thing that he hath spoken