Isaiah 38:5-8

5“Go, and say to Hezekiah, thus says Adonai, the God of your father David: ‘I have heard your prayer and I have seen your tears. Behold, I will add 15 years to your life.

6I will deliver you and this city from the hand of the king of Assyria; I will defend this city.’

7“Now this will be the sign to you from Adonai, that Adonai will do this word He has spoken:

8Behold, I will cause the shadow on the stairs, which went down with the sun on the sundial of Ahaz, to turn back ten steps.” So the sun’s shadow went back ten steps on the sundial on which it had gone down.