Isaiah 38:5-8

5Go, and say to Hezekiah, Thus saith Yhwh, 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.

6And I will deliver thee and this city out of the hand of the king of Assyria: and I will defend this city.

7And this shall be a sign unto thee from Yhwh, that Yhwh will do this thing that he hath spoken;

8Behold, I will bring again the shadow of the degrees, which is gone down in the sun dial of Ahaz, ten degrees backward. So the sun returned ten degrees, by which degrees it was gone down.1