Matthew, Mark, and Luke together record that on Jesus' final visit to Jerusalem, he went to the Temple and cleared out all the vendors; he also taught there regularly. Those who considered themselves in charge of the Temple came to ask him: Exactly what authority did you have to do that? All three of the earlier gospels record that, at this point, Jesus referred to John the Baptist: You tell me what authority he had to baptize, and I'll tell you what authority I had to do that.
Why did Jesus starting talking about John the Baptist? Was he changing the subject? No; in all three of the gospels, the people understood his point in asking about John the Baptist : "If we say, 'From heaven' then he will say, 'Why did you not believe him?'" They knew full well that John the Baptist said Jesus' authority was from heaven. So if they admitted that John the Baptist was a prophet, they would have to acknowledge that Jesus was even greater, as John had said. That was why they couldn't acknowledge John the Baptist: John the Baptist testified about Jesus. All Jesus would have to say then is, "Why did you not believe him?" and they knew it.
If we look at how these "authorities" handled truth, we can see that they handled truth the same way that many people handle morality: whatever is to their benefit is considered right, and whatever is not to their benefit is questionable or wrong. They didn't just draw the lines of "morality" to suit themselves, they did the same to "truth" as well. They did not look for what was right; they calculated what was to their benefit. Such is the way of the world. "We do not know," they answered about John the Baptist. But they sure sounded as if they knew; they just didn't want to admit it.
Jesus did not let the conversation end there with their evasion. He told a parable of the wicked tenants who were about to get evicted -- after they had killed the messengers, and would finally kill the owner's son. How did the authorities react? "They knew he had spoken this parable against them." (Amazing how, in their minds, it was always about them. Whether they could acknowledge Jesus was about them. Whether they could acknowledge John the Baptist was about them. The parable is about them.) Part of the parable was about them -- they were the wicked tenants who didn't mind killing someone so that they could stay in charge. But did they recognize that Jesus put himself in a different category than the messengers who came before? In Jesus' parable, he was the son of the owner. He was the heir.
If they knew their Scriptures then they would have understood Jesus' reference to a vineyard:
For the vineyard of the LORD of hosts is the house of Israel, and the men of Judah are the garden of his delight. He looked for justice [as the harvest of the vineyard] but saw oppression. He looked for righteousness [as fruit] but heard cries of distress. (Isaiah 5:7)Matthew, Mark, and Luke all record the point plainly enough: Jesus' answer about his authority was that he was above any messenger who had come before: he was uniquely the son and heir of the LORD.