Isaiah 38:5-7

“Go and say to Hezekiah, Thus says the LORD, the God of David your father: I have heard your prayer; I have seen your tears. Behold, I will add fifteen years to your life. I will deliver you and this city out of the hand of the king of Assyria, and will defend this city. “This shall be the sign to you from the LORD, that the LORD will do this thing that he has promised