Jewel Mirror Samadhi Talks

The Song of the Precious Mirror Samadhi (Chinese: 寶鏡三昧歌; pinyin: Bǎojìng sānmèi gē; Wade–Giles: Pao-ching San-mei-ke; Japanese: Hōkyō Zammai; also translated as Song of the Jeweled Mirror Samadhi and Sacred Mirror Samadhi) is a Zen poem in Classical Chinese that appeared during the Song dynasty. The work is often attributed to Dongshan Liangjie (Japanese: Tōzan Ryōkai), the co-founder of the Caodong/Sōtō branch of Zen Buddhism, although modern research suggests this is unlikely.

From Song of the Precious Mirror Samadhi on Wikipedia