In Zen, it is said, “open mouth, already a mistake.”
The words a teacher uses are not truth but pointers to truth. If someone believes what a teacher is saying, they have missed the point! What is being pointed to, here, now, are not concepts to be believed but truths to be realized. When the teacher uses words to point, some people take a good and honest look for themselves, see, recognize and realize the truth. Others argue about concepts! And that is when the teacher realizes once again, “open mouth, already a mistake.” And yet their realization happened because of the compassion and patience of their own teachers, and so compassion and patience keeps them making the same mistake over and over again. And sometimes a light suddenly flashes on, shines brightly and makes all the mistakes well worth while!
Zen also suggests we not mistake the finger for the moon it point to.
The Heart of Conscious Living 