The Chan shout. Someone would jump out from behind a tree or bush and shout at a novice.
https://en.wikipedia.org/wiki/Katsu_(Zen)
Katsu (Japanese: 喝; Cantonese: About this soundhot3 (help·info), Pinyin: hè, Wade-Giles: ho) is a shout that is described in Chán and Zen Buddhism encounter-stories, to expose the enlightened state (Japanese: satori) of the Zen-master, and/or to induce initial enlightenment experience in a student.[1][2] The shout is also sometimes used in the East Asian martial arts for a variety of purposes; in this context, katsu is very similar to the shout kiai.[
Use[edit]
The katsu shout, insofar as it represents a kind of verbal harshness and even violence, can be considered a part of the Mahāyāna Buddhist doctrine of "skill-in-means" (Sanskrit: upāya-kauśalya), which essentially teaches that even an action or practice which seems to violate Buddhist moral guidelines—in this case, the Noble Eightfold Path's injunction against "abusive speech"[11]—is permissible, and even desirable, so long as it is done with the aim of ultimately putting an end to suffering and introducing others to the dharma, or teachings of Buddhism.
The most celebrated and frequent practitioner of the katsu was the Chinese master Línjì Yìxuán (?–866), and many examples of his use of the shout can be found in the Línjì-lù (臨済錄; Japanese: Rinzai-roku), or Record of Linji, the collection of Linji's actions and lectures:
A monk asked, "What is the basic meaning of Buddhism?" The Master gave a shout.[12] The monk bowed low. The Master said, "This fine monk is the kind who's worth talking to!"[13]
The use of the katsu stands in a tradition of antinomian methods, such as striking disciples with a stick or a fly whisk,[14] which developed within the Mǎzǔ Dàoyī (709–788) lineage.[15] Linji greatly developed and used the katsu technique. In one of his lectures, often termed as "Linji's Four Shouts"[16] he distinguished four different categories of katsu:
The Master said to a monk, "At times my shout is like the precious sword of the Diamond King. At times my shout is like a golden-haired lion crouching on the ground. At times my shout is like the search pole and the shadow grass. At times my shout doesn't work like a shout at all. Do you understand?" The monk started to answer, whereupon the Master gave a shout.[17]