1 Kings 13:3
"And he gave a sign the same day, saying, This is the sign which the LORD hath spoken; Behold, the altar shall be rent, and the ashes that are upon it shall be poured out."
Cross References (ranked by relevance)
For the Jews require a sign, and the Greeks seek after wisdom:
Then answered the Jews and said unto him, What sign shewest thou unto us, seeing that thou doest these things?
And he said unto him, If now I have found grace in thy sight, then shew me a sign that thou talkest with me.
And Hezekiah said unto Isaiah, What shall be the sign that the LORD will heal me, and that I shall go up into the house of the LORD the third day?
Hezekiah also had said, What is the sign that I shall go up to the house of the LORD?
And this shall be a sign unto you, saith the LORD, that I will punish you in this place, that ye may know that my words shall surely stand against you for evil:
And this shall be a sign unto thee, that shall come upon thy two sons, on Hophni and Phinehas; in one day they shall die both of them.
And Moses and Aaron went in unto Pharaoh, and they did so as the LORD had commanded: and Aaron cast down his rod before Pharaoh, and before his servants, and it became a serpent.