Mark 11:33

And they answered Jesus and say, We know not. And Jesus saith unto them, Neither tell I you by what authority I do these things.

We know not ... This, on the part of the religious leaders, may be taken in only two ways. If it was true that they knew not, as alleged by Grant, that "they could not answer,"[14] then in such a circumstance they should have confessed their ignorance, resigned their pretensions as interpreters of the will of God, and cast themselves at Jesus' feet. On the other hand, if what they said about not knowing was a falsehood (and Mark left no doubt at all that it was a falsehood), then those evil men thereby forfeited the last vestiges of any respect to which they might have been entitled had mere ignorance been their fault. By their denial of what they certainly did know, namely, that John's baptism was of God, they fully identified themselves with Satan; but even an effective satanic witness they declined to make through cowardice prompted by fear of the people. Their appearance in this event is as contemptible as that of any other assembly of sons of the devil in all history. One may only marvel at "scholars" who defend the reputation of such men.

Neither tell I you by what authority I do these things. Jesus did not say "I cannot tell," but that "I will not tell." Such questioners were in no wise entitled to any factual reply.