Mark 11:30

And say unto him, By what authority doest thou these things? and who gave thee this authority to do these things?

And Jesus answered and said unto them, I will also ask of you one question, and answer me, and I will tell you by what authority I do these things.

And they reasoned with themselves, saying, If we shall say, From heaven; he will say, Why then did ye not believe him?

But if we shall say, Of men; they feared the people: for all men counted John, that he was a prophet indeed.