From: Mark 11:27-33
 And they (Jesus and his disciples) came to Jerusalem. And as he was walking in the temple, the chief priests and the scribes and the elders came to him,  and they said to him, "By what authority are you doing these things, or who gave you this authority to do them?"  Jesus said to them, "I will ask you a question; answer me, and I will tell you by what authority I do these things.  Was the baptism of John from heaven or from men? Answer me."  And they argued with one another, "If we say, 'From heaven,' he will say, 'Why then did not you not believe him?'  But shall we say, 'From men'?"--they were afraid of the people, for all held that John was a real prophet.  So they answered Jesus, "We do not know." And Jesus said to them, "Neither will I tell you by what authority I do these things."
27-33. Those who put this question to Jesus are the same people as, some days earlier, sought to destroy him (cf. Mk 11:18). They represent the official Judaism of the period (cf. note on Mt 2:4). Jesus had already given proofs and signs of being the Messiah, in his miracles and preaching; and St. John the Baptist had borne witness about who Jesus was. This is why, before replying, our Lord asks them to recognize the truth proclaimed by the Precursor. But they do not want to accept this truth; nor do they want to reject it publicly, out of fear of the people. Since they are not ready to admit their mistake, any further explanation Jesus might offer would serve no purpose.
This episode has many parallels in everyday life: anyone who seeks to call God to account will be confounded.
Source: "The Navarre Bible: Text and Commentaries". Biblical text taken from the Revised Standard Version and New Vulgate. Commentaries made by members of the Faculty of Theology of the University of Navarre, Spain. Published by Four Courts Press, Kill Lane, Blackrock, Co. Dublin, Ireland, and by Scepter Publishers in the United States. We encourage readers to purchase The Navarre Bible for personal study. See Scepter Publishers for details.