“Then answered the Jews and said unto him, What sign shewest thou unto us, seeing that thou doest these things?”
King James Version (KJV)
2:18 Then answered the Jews - Either some of those whom he had just driven out, or their friends: What sign showest thou? - So they require a miracle, to confirm a miracle!
Joh 2:18 What sign? The Jewish officials demand some sign that would demonstrate that he had authority over the temple.