Mark 11:29-33

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.

The baptism of John, was it from heaven, or of men? answer me.

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.

And they answered and said unto Jesus, We cannot tell. And Jesus answering saith unto them, Neither do I tell you by what authority I do these things.