What is extracted from the interactions between a master and disciple, or Zen lecture transcripts that record the actions of a master, is called a Koan (precedent) and various collections have been compiled since the Song dynasty; but enlightenment is not something that can be communicated with words, so when people today try to understand the text, the Koan itself refuses them.
師匠と弟子のやりとりや、師匠の振舞を記録した禅語録から、抜き出したものが公案（判例）とよばれ、宋代からさまざまな集成が編まれてきたが、悟りは言葉では伝えられるものではなく、現代人の文章理解で読もうとすると公案自体が拒絶する。