Yaoshan Weiyan (Yueh-shan Wei-yen; Yakusan Igen), 745-828 or 750-834. The Thirty-Sixth Ancestor. A Dharma-heir of Shitou Xiqian. His Dharma-heirs were Yunyan Tansheng (from his heir Dongshan Liangjie the Caodong Lineage began) and Chuanzi Decheng, and Daowu Yuanzhi. He also studied with Mazu Daoyi, who had given Transmission to Daowu before Daowu studied with Yaoshan and received his Transmission. He appears in the Sayings and Doings of Dongshan (Dongshan yulu) 91, 110, 111, 112, 113. He appears in Records of Silence 5, 7. See Denkoroku Chapter 37. See also the encounters between Yaoshan and Shitou and then Mazu in Dogen's Uji.
Dogen zenji recounts the following story in Shobogenzo 30: Kangin: “The Ancestor Yaoshan usually did not allow sutra study but one day a monk found him looking at an open scroll. The monk said, “Teacher, you usually do not allow us to read the sutras, so why are you yourself reading them?”
“I just need to rest my eyes on something.”
The monk replied, “Well, can I use the same excuse?”
The master replied, “If you were to look at the sutras you’d burn a hole through their cover.”