Blue Cliff Record
A number of kōan dialogues feature Yunyan and his fellow student Daowu Yuanzhi. Case 54 of the Book of Equanimity, Case 89 of the Blue Cliff Record, case 105 from Dōgen's Shinji Shōbōgenzō, and the chapter "Kannon" from Dōgen's Kana Shōbōgenzō, and all involve the same story in which Yunyan and Daowu discuss the purpose of Avalokiteśvara's many hands and eyes. The precise intention of the story varies with each version.