Luke 20
Jesus' authority is questioned
And it came to pass, that on one of those days, as he taught the people in the temple, and preached the gospel, the chief priests and the scribes came upon him with the elders, And spake unto him, saying, Tell us, by what authority doest thou these things? or who is he that gave thee this authority? And he answered and said unto them, I will also ask you one thing; and answer me: The baptism of John, was it from heaven, or of men? And they reasoned with themselves, saying, If we shall say, From heaven; he will say, Why then believed ye him not? But and if we say, Of men; all the people will stone us: for they be persuaded that John was a prophet. And they answered, that they could not tell whence it was. And Jesus said unto them, Neither tell I you by what authority I do these things.
While Jesus is teaching in the temple, the chief priests, scribes and elders demand to know by what authority he acts. He replies with a question of his own: was John's baptism from heaven or from people? Fearing either answer, since the first would condemn their unbelief and the second would anger the crowd who believe John was a prophet, they say they do not know, and Jesus declines to answer them.
What does this mean?
"These things" probably refers to his action in the temple and his teaching there. "From heaven" is a reverent way of saying "from God."
Historical context
The chief priests controlled the temple and, with scribes and elders, led the council (Sanhedrin). Their fear that the people would stone them shows how popular John had been.
Why does it matter?
Jesus' counter-question links his authority with John's: both come from God, as Luke's opening chapters have shown. This begins a series of challenges in the temple (20:1–44), each of which Jesus turns back on his questioners.
Editorial notes, not scripture.