Luke 20:3

And he answered [and] said to them, "I also will ask you a question, and you tell me:

"Why do your disciples break the tradition of the elders? For they do not wash their hands when they eat {a meal}."

and if I ask [you], you will never answer!

Let your speech always [be] with grace, seasoned with salt, so that [you] may know how it is necessary for you to answer each 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 [you], you will never answer!