In the biography of Keizan Jōkin （1264-1325） which was established in the Edo period, it is written that the verse 黒漆崑崙夜裏走 represents Keizan’s enlightenment. The source of the verse had been considered to be the Song period Wudeng huiyuan 五灯会元. However, the verse is not found in that text. Monks from the Taigen lineage of the Sōtō school started to use the verse, which appeared for the first time in the work of Kokai Chūsan 瑚海仲珊 （1390-1469）. After that, the verse became accepted widely in Zen schools through the sixteenth century.
Therefore, the author of Keizan’s biography in the Edo period attempted to proclaim the famous phrase as originated in Keizan and portray his authority by utilizing the famous phrase established by the medieval Taigen lineage as a phrase that expresses Keizan’s enlightenment.
