There was once a monk whose name was Gutei. And whenever people came to him with a question about buddhism, he would hold up a finger. That is the only answer he would give. Well, he had an attendant, and one day somebody came to the temple to inquire into the teachings being given there. The master was apparently out, but his attendent was there. So, the investigator asked, "What is your teaching here?" And the attendant held up a finger.
But in fact, the master had been there, he was peaking from behind a screen. And he came out to this boy after, and asked, "What is the fundamental teaching of Buddhism?" and the boy held up a finger.
Instantly, the master drew a knife and cut it off. The boy was naturally very upset, and ran away screaming. And so the master, yelled, "Hey come back". And as the boy came back, the master asked "What is the fundamental teaching of Buddha?" And he went to hold up his finger, but it wasn't there. And thus the attendant was enlightened.