2 Kings 20:8-11

8Meanwhile, Hezekiah had said to Isaiah, “What sign will the Lord give to prove that he will heal me and that I will go to the Temple of the Lord three days from now?”

9Isaiah replied, “This is the sign from the Lord to prove that he will do as he promised. Would you like the shadow on the sundial to go forward ten steps or backward ten steps?”

10“The shadow always moves forward,” Hezekiah replied, “so that would be easy. Make it go ten steps backward instead.”

11So Isaiah the prophet asked the Lord to do this, and he caused the shadow to move ten steps backward on the sundial of Ahaz!