Baizhang Huaihai

Baizhang Huaihai (Chinese: 百丈懷海; pinyin: Bǎizhàng Huáihái; Wade-Giles: Pai-chang Huai-hai; Japanese: Hyakujō Ekai) (720–814) was a Chinese Zen master during the Tang Dynasty. He was a dharma heir of Mazu Daoyi (Wade-Giles: Ma-tsu Tao-i). Baizhang's students included Huangbo, Linji and Puhua.

According to traditional Chan/Zen accounts, Baizhang established an early set of rules for Chan (Chinese Zen) monastic discipline, the Pure Rules of Baizhang (Chinese: 百丈清規; pinyin: Bǎizhàng qīngguī; Wade–Giles: Pai-chang ch'ing-kuei),Korean: 백장청규) It was practiced in Ta-chih shou-sheng ch'an-ssu (Jp. Daichijusho-zenji), founded by Baizhang. This monastery contained a monks hall, an innovation which became typical for Chán:

During periods of ascetic practice the monks would sleep on the same straw mat on which they sat in meditation and on which, according to defined ritual, they took their meals. Both the lifestyle Pai-chang spelled out as well as the architectural form of his monastery became models for later Zen monasteries".

Some believe these rules developed much later in Chan history, and are agreed by the monks Taixu and Hsu Yun.

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