In meeting a man along the way, greet him neither with words nor with silence. Now tell me, how will you greet him?
— An old Zen koan
A kōan (公案?)/ˈkoʊ.ɑːn/; Chinese: 公案; pinyin: gōng’àn; Korean: 공안 (kong’an); Vietnamese: công án) is a story, dialogue, question, or statement, which is used in Zen practice to provoke the “great doubt” and test a student’s progress in Zen practice. – https://en.wikipedia.org/wiki/K%C5%8Dan
Examples of traditional kōans
Does a dog have Buddha-nature
Main article: Mu (negative)
A monk asked Zhàozhōu, “Does a dog have Buddha nature or not?” Zhaozhou said, “Wú”.
(“Zhaozhou” is rendered as “Chao-chou” in Wade-Giles, and pronounced “Joshu” in Japanese. “Wu” appears as “mu” in Japanese, meaning “no”, “not”, “nonbeing”, or “without” in English. This is a fragment of Case #1 of the Wúménguān. However, another koan presents a longer version, in which Zhaozhou answered “yes” in response to the same question asked by a different monk: see Case #18 of the Book of Serenity.)
The sound of one hand
Two hands clap and there is a sound. What is the sound of one hand? (隻手声あり、その声を聞け)
— Hakuin Ekaku
Victor Hori comments:
…in the beginning a monk first thinks a kōan is an inert object upon which to focus attention; after a long period of consecutive repetition, one realizes that the kōan is also a dynamic activity, the very activity of seeking an answer to the kōan. The kōan is both the object being sought and the relentless seeking itself. In a kōan, the self sees the self not directly but under the guise of the kōan … When one realizes (“makes real”) this identity, then two hands have become one. The practitioner becomes the kōan that he or she is trying to understand. That is the sound of one hand.[web 6]
Main article: Original face
Huìnéng asked Hui Ming, “Without thinking of good or evil, show me your original face before your mother and father were born.” (This is a fragment of case #23 of the Wumenguan.)
Killing the Buddha
If you meet the Buddha, kill him. (逢佛殺佛)
Thinking about the Buddha as an entity or deity is delusion, not awakening. One must destroy the preconception of the Buddha as separate and external before one can become internally as their own Buddha. Zen master Shunryu Suzuki wrote in Zen Mind, Beginner’s Mind during an introduction to Zazen,
Kill the Buddha if the Buddha exists somewhere else. Kill the Buddha, because you should resume your own Buddha nature.
One is only able to see a Buddha as he exists in separation from Buddha, the mind of the practitioner is thus still holding onto apparent duality.
A student asked Master Yun-Men (A.D. 949) “Not even a thought has arisen; is there still a sin or not?” Master replied, “Mount Sumeru!”
A monk asked Dongshan Shouchu, “What is Buddha?” Dongshan said, “Three pounds of flax.” (This is a fragment of case #18 of the Wumenguan as well as case #12 of the Blue Cliff Record.)
A monk asked Zhaozhou, “What is the meaning of the ancestral teacher’s (i.e., Bodhidharma’s) coming from the west?” Zhaozhou said, “The cypress tree in front of the hall.” (This is a fragment of case #37 of the Wumenguan as well as case #47 of the Book of Serenity.)