Isaiah 38:6

4Then the LORD’s word came to Isaiah, saying,

5“Go, and tell Hezekiah, ‘The LORD, the God of David your father, says, “I have heard your prayer. I have seen your tears. Behold, I will add fifteen years to your life.

6I will deliver you and this city out of the hand of the king of Assyria, and I will defend this city.

7This shall be the sign to you from the LORD, that the LORD will do this thing that he has spoken.

8Behold, I will cause the shadow on the sundial, which has gone down on the sundial of Ahaz with the sun, to return backward ten steps.”’” So the sun returned ten steps on the sundial on which it had gone down.