2 Kings 20:8-9

8Then Hezekiah said to Isaiah, “What will be the sign that Adonai will heal me, and that I should go up to the House of Adonai on the third day?”

9Then Isaiah said, “This will be the sign to you from Adonai, that Adonai will do this word He has spoken: Should the shadow go forward ten steps or go back ten steps?”