This is the third in a series of koans centred on the natural world. The koan is Case 38 in the Mumonkan

Books used in the teisho:

Zen's Chinese Heritage by Andy Ferguson and The Gateless Barrier by Robert Aitken.

The three fruits of Zen practice are, 1. joriki or concentration, 2. kensho, or seeing your True Nature and 3. mujo do no taigen, or embodiment of the peerless way.

Source: Ruben Habito's Foreword to The Flowing Bridge by Elaine MacInnes, Wisdom 2007.

More from the Shobogenzo Zuimonki on effort.

Source: A Primer of Soto Zen translated by Reiho Masunaga.

Sources: How to Train an Ox and Primer of Soto Zen.

Dōgen's Fukan Zazengi, "General Recommendations for Doing Zazen"

Source: How to Raise an Ox by Francis Dojun Cook.

Dōgen's talks from the Eihei Kōruku, Part Two.

Sources: Dōgen's Extensive Record: Eihei Kōroku translated by Taigen Dan Leighton and Shohaku Okumura, and The Art of Just Sitting edited by John Daido Loori.

Dōgen's talks from the Eihei Kōruku, Part One.

Source: Dōgen's Extensive Record: Eihei Kōroku translated by Taigen Dan Leighton and Shohaku Okumura.

Dōgen's early life.

Source: Zen Master Dōgen - An Introduction with Selected Writings by Yūhō Yokoi with Daizen Victoria.

Looking at all ten cardinal precepts from the angle of Bodhidharma's One Mind teachings.

Source(s): Invoking Reality by John Daido Loori.

This is the second in a series of koans centred on the natural world. The koan is Case 37 in the Mumonkan, Zhaozhou's Cypress Tree in the Courtyard.

Sources: Pilgrim at Tinker's Creek by Annie Dillard and Two Zen Classics by Katsuki Sekida.