Shinji Shōbōgenzō

The Shinji Shōbōgenzō (真字正法眼蔵) or True Dharma Eye 300 Cases (Shōbōgenzō Sambyakusoku), or Treasury of the True Dharma Eye (Mana Shōbōgenzō), compiled by Eihei Dōgen in 1223–1227, was first published in Japanese in 1766. The literary sources of the Shinji Shōbōgenzō are believed to have been the Keitoku Dentōroku and the Shūmon Tōyōshū. It is written in Chinese, the language of the original texts from which the kōans were taken.

Background
Regardless of a few instances where Dōgen criticized the study of kōans, legend states that the young monk stayed up all night copying the Blue Cliff Record before his journey China (although this story is likely apocryphal, given the great length of the text). Dōgen's first teacher, Eisai, taught the importance of kōan introspection. While establishing the Kōshōhōrin-ji, Dōgen gathered the three hundred kōans featured in the Shinji Shōbōgenzō.