27 Again they entered Jerusalem. As Jesus was walking through the Temple area, the leading priests, the teachers of religious law, and the elders came up to him. 28 They demanded, "By what authority are you doing all these things? Who gave you the right to do them?" 29 "I'll tell you by what authority I do these things if you answer one question," Jesus replied. 30 "Did John's authority to baptize come from heaven, or was it merely human? Answer me!" 31 They talked it over among themselves. "If we say it was from heaven, he will ask why we didn't believe John. 32 But do we dare say it was merely human?" For they were afraid of what the people would do, because everyone believed that John was a prophet. 33 So they finally replied, "We don't know." And Jesus responded, "Then I won't tell you by what authority I do these things."
Matthew Henry's Commentary on Mark 11:27-33
Commentary on Mark 11:27-33
(Read Mark 11:27-33)
Our Saviour shows how near akin his doctrine and baptism were to those of John; they had the same design and tendency, to bring in the gospel kingdom. These elders did not deserve to be taught; for it was plain that they contended not for truth, but victory: nor did he need to tell them; for the works he did, told them plainly he had authority from God; since no man could do the miracles which he did, unless God were with him.