Mark 11:33

And they answered and said unto Jesus
Being reduced by this dilemma to the greatest streight and difficulty;

we cannot tell:
they could, if they would, but they did not care to tell; they knew if they did, they should expose themselves one way or other:

and Jesus answering, saith unto them, neither do I tell you by what
authority I do these things; (See Gill on Matthew 21:27).