2 Kings 20:4-8

4Then it came to pass, before Isaiah was gone out of the middle court, that the word of Adonai came to him, saying:

5“Return, and say to Hezekiah the leader of My people, thus says Adonai, the God of your father David: ‘I have heard your prayer and I have seen your tears. Behold, I am going to heal you. On the third day you will go up to the House of Adonai.

6Then I will add 15 years to your life. I will deliver you and this city from the hand of the king of Assyria; I will defend this city for My own sake, and for My servant David’s sake.’”

7Then Isaiah said, “Take a cake of figs.” So they took one and laid it on the boil, and he recovered.

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?”