Charles Spurgeon Commentary Matthew 21:24-27

"And Jesus answered and said unto them, I also will ask you one question, which if ye tell me, I likewise will tell you by what authority I do these things. The baptism of John, whence was it? from heaven or from men? And they reasoned with themselves, saying, If we shall say, From heaven; he will say unto us, Why then did ye not believe him? But if we shall say, From men; we fear the multitude; for all hold John as a prophet. And they answered Jesus, and said, We know not. He also said unto them, Neither tell I you by what authority I do these things." — Matthew 21:24-27 (ASV)

He carried the war into the enemy's camp. He answered his accusers by asking them a question which they could not answer in either way without condemning themselves.