The Codeless Code - Tales to make wiser programmers.(thecodelesscode.com)

    It is said that Master Gutei would always raise a finger wisely when
    teaching about Zen. Now in his monastery there were young boys studying
    to be Zen masters themselves, and one boy, when he was asked questions
    by his teachers, began also to raise his finger when answering Zen
    questions. The teachers told Gutei about this and Gutei summoned him to
    a rare audience with the master! Gutei asked him a simple question which
    the boy could answer confidently, and the boy raised his finger as he
    responded.

    Gutei immediately grabbed the finger and in one motion cut it off with a
    concealed knife. The boy screamed and ran to the far side of the room.
    Gutei called him to stop and return, and the boy recovered his composure
    and plodded back in front of the master. Gutei raised his own finger
    before the boy, and in that moment the boy was enlightened.

    Indeed, on his deathbed Gutei's last words were: "My teacher Tenryu
    taught me the Zen in my finger, and though I used it my whole life, I
    couldn't use it up."