John Gill Commentary Luke 20:8

"And Jesus said unto them, Neither tell I you by what authority I do these things." — Luke 20:8 (ASV)

And Jesus said to them
Since they would not give him a direct answer to his question:

neither tell I you by what authority I do these things ;
nor was there any need of it; they might easily perceive by what he had said, from where he professed to have received his authority, from God, and not men; (See Gill on Matthew 21:27).