Here's a legitimate question: who has legitimate authority? For example, who can access your medical records? Who gets to make the laws we're required to follow? Who has authority to issue orders on the field of battle? Luke 20:1–18 concerns authority of the most important kind: the authority to bring about God's redemptive purposes, to save, to forgive, to set prisoners free, to rule as king over God's kingdom. When Jesus showed up to the temple in Jerusalem he began to preach the good news on the basis of his authority as God's king. That's when he was interrupted by a question, "by what authority. . .?"