Isaiah 38:4-8

4Then the word of the Lord came to Isaiah, saying,

5“Go and say to Hezekiah, ‘For the Lord, the God of David your father says this, “I have heard your prayer, I have seen your tears; listen carefully, I will add fifteen years to your life.

6I will rescue you and this city from the hand of the king of Assyria; and I will defend this city [Jerusalem].” ’

7“This shall be the sign to you from the Lord, that the Lord will do this thing that He has spoken:

8Listen carefully, I will turn the shadow on the stairway [denoting the time of day] ten steps backward, the shadow on the stairway (sundial) of Ahaz.” And the sunlight went ten steps backward on the stairway where it had [previously] gone down.