, or of a kà Âan is a proof of solution of the case riddle, but not the solution itself. In Zen Buddhism, kà Âan is used both as a meditation device and as an expression of – a radical experiential insight into the nature of things and the self alike. A capping phrase is supposedly an articulation of such enlightening experience, most of the time in verse. According to Victor Sà Âgen Hori the use of jakugo dates to the Song dynasty (AD 960 - 1270) and was developed from classical Chinese "literary games".
V. Sà Âgen Hori describes the process of the kà Âan training as follows: "Rinzai monasteries in Japan vary in the way they conduct kà Âan practice, but in the Myà Âshin-jiâÂÂDaitoku-ji branch, when a monk has passed a kà Âan the Zen teacher will instruct him to bring a 'capping phrase' ... The monk selects a verse or phrase that expresses the insight he has had while meditating on the kà Âan. He searches for this capping phrase in one of the several Zen phrase books that have been especially compiled for this purpose. If the monk continues into advanced stages of the Rinzai Zen kà Âan curriculum, he will receive further literary assignments: the writing of explanations in Japanese, called kakiwake æ¸ãÂÂÃ¥ÂÂãÂÂ, and the composition of Chinese-style poetry, called nenrà ÂãÂÂæÂÂå¼ ... The research and writing required to complete kakiwake and nenrà  writing assignments can consume considerable amounts of time during the later stages of a monk's stay in the monastery." (pp. 3âÂÂ4.)