Isaiah 38:7

So Gideon said to Him, “If now I have found favor in Your eyes, then do a sign for me that it is You who speak with me.

Then he gave a miraculous sign the same day, saying, “This is the miraculous sign which Yahweh has spoken, ‘Behold, the altar shall be torn apart and the ashes which are on it shall be poured out.’”

Now in the fourteenth year of King Hezekiah, Sennacherib king of Assyria came up against all the fortified cities of Judah and seized them.

In those days Hezekiah became ill to the point of death. And Isaiah the prophet the son of Amoz came to him and said to him, “Thus says Yahweh, ‘Set your house in order, for you shall die and not live.’”

And Isaiah said, “This shall be the sign to you from Yahweh, that Yahweh will do the thing that He has spoken: shall the shadow go forward ten steps or turn back ten steps?”

In those days Hezekiah became sick to the point of death; and he prayed to Yahweh, and Yahweh spoke to him and gave him a miraculous sign.

Even in the matter of the envoys of the rulers of Babylon, who sent to him to inquire of the miraculous sign that had happened in the land, God left him alone only to test him, that He might know all that was in his heart.

“Ask a sign for yourself from Yahweh your God; make it deep as Sheol or high as heaven.”

And the king of Assyria sent Rabshakeh from Lachish to Jerusalem to King Hezekiah with a heavy military force. And he stood by the conduit of the upper pool on the highway of the fuller’s field.

Then Hezekiah had said, “What is the sign that I shall go up to the house of Yahweh?”