2 Kings 20:5-8

5"Turn back, and say to Hezekiah the leader of my people, Thus says the Lord, the God of David your father: I have heard your prayer; I have seen your tears. Behold, I will heal you. On the third day you shall go up to the house of the Lord,

6and I will add fifteen years to your life. I will deliver you and this city out of the hand of the king of Assyria, and I will defend this city for my own sake and for my servant David's sake."

7And Isaiah said, "Bring a cake of figs. And let them take and lay it on the boil, that he may recover."

8And Hezekiah said to Isaiah, "What shall be the sign that the Lord will heal me, and that I shall go up to the house of the Lord on the third day?"