Luke 20:3

And he answering said to them, I also will ask you a question; and tell me:

Why do thy disciples transgress the tradition of the elders? for they wash not their hands when they eat bread.

and if I ask, ye will not answer.

Let your speech be always with grace, seasoned with salt, that ye may know how ye ought to answer every one.

Treasury of Scripture Knowledge

And he answered and said unto them, I will also ask you one thing; and answer me:

and if I ask, ye will not answer.