Gutei raised his finger whenever he was asked a question about Zen. A boy attendant began to imitate him in this way. When a visitor asked the boy what his master had preached about, the boy raised his finger.
Gutei heard about the boy's mischief, seized him and cut off his finger with a knife. As the boy screamed and ran out of the room, Gutei called to him. When the boy turned his head to Gutei, Gutei raised up his own finger. In that instant the boy was enlightened.
When Gutei was about to die, he said to the assembled monks,"I received this one-finger Zen from Tenryu. I used it all my life and yet could not exhaust it" and then he passed away.
This is a fun Koan. The story has some zing but it might also seem a bit gruesome. How could a Zen master cut off someone's finger? Koans often mess with your sensibilities, with purpose. Now how do you find your way back to samadhi?
It is likely this event never happened. It doesn't matter. The story is metaphorical and it has a lesson to teach. This lesson is a straightforward understanding of how kensho works. Each koan in the Mumonkan is placed where it is for a reason. The lessons are to be learned sequentially. Mu teaches us our most basic skill, samadhi. Hyakujo and the Fox is a cautionary tale and also a lesson in cause and effect. Now that we have excited our thinking mind let's return to samadhi. Maybe not so easy. it is easy to think that some wonderful, even life changing, new understanding is enlightenment but it is not, at least not completely. Just as important, or maybe more important is that experience, that state of mind, from which the new understanding arose.
When I was practicing with Sezaki Roshi and I had my first deep experience, Sezaki told me that now that I have had my first deep experience I should create a structure to allow me to come back to the experience. I was not sure what he meant. I confused this wonderful new understanding with the state of mind that allowed the new insight. Coming from an intellectual background I spent a lot of time building an intellectual structure of understanding. But then I couldn't seem to pass any more koans. Though I didn't quite admit it to myself I knew that my "enlightenment" was lacking. I continued to diligently practice meditation every day and my every day meditation continued to deepen. And my insight continued to deepen. But then something as simple as receiving more responsibility at work was enough to throw my meditation off. And I even stopped meditating for a while. And then even though I had all that insight even that just became a memory and once again I was prone to the normal anxieties of life. In other words the real power is in meditation and one must deepen it until it becomes an impenetrable bulwark standing up to all the vicissitudes of life.
Gutei held up that one finger and that is his teaching. See the world as One, without duality! This is not just an idea something you can talk yourself into or even something you hold as a memory from a previous experience. It is something that must be experienced again and again. And yet if you hold on to this idea, if you hold on to any idea the experience will elude you. Cut off all ideas, enter samadhi, and it will all be clear.