Yaoshan Weiyan

Yaoshan Weiyan was a student of Shitou Xiqian who also studied with Mazu Daoyi, bridging the two great branches of Tang dynasty Chan. He settled on Mount Yao and established a community known for its rigorous practice and spare, penetrating teaching style. His dialogues reveal a master who combined Shitou's subtlety with a directness that left no room for evasion.

Yaoshan is perhaps best known for the exchange in which a monk asked what he was thinking while sitting so still. He replied, "I'm thinking of not-thinking." The monk asked how one thinks of not-thinking, and Yaoshan said, "Non-thinking." This exchange became a foundational text for the Caodong tradition's understanding of zazen—a practice that is neither the pursuit of thinking nor its suppression, but something altogether beyond that duality. His principal students included Daowu Yuanzhi and Yunyan Tansheng, through whom the Caodong lineage descended.