The year and place of Sengcan's birth is unknown, as is his family name.
Huike
It is said that Sengcan (old spelling: Tsang Tsan) was over forty years old when he first met Huike in 536 and that he stayed with his teacher for six years. (Dumoulin, p 97) It was Huike who gave him the name Sengcan (“Gem Monk”).
The Transmission of the Lamp entry on Sengcan begins with a koan-like encounter with Huike:
Sengcan: I am riddled with sickness. Please absolve me of my sin.
Huike: Bring your sin here and I will absolve you.
Sengcan (after a long pause): When I look for my sin, I cannot find it.
Huike: I have absolved you. You should live by the Buddha, the Dharma, and the Sangha.
There are discrepancies about how long Sengcan stayed with Huike. The Transmission of the Lamp records that he “attended Huike for two years” after which Huike passed on the robe of Bodhidharma and Bodhidharma's Dharma (generally considered to be the Lankavatara Sutra), making him the Third Patriarch of Chan.
According to Dumoulin, in 574 the accounts say that he fled with Huike to the mountains due to the Buddhist persecution underway at that time. However, the Lamp records claim that after giving Sengcan Dharma transmission, Huike warned Sengcan to live in the mountains and “Wait for the time when you can transmit the Dharma to someone else.” as a prediction made to Bodhidharma (Huike's teacher) by Prajnadhara, the twenty-seventh Chan ancestor in India, foretold of a coming calamity.
After receiving transmission, Sengcan lived in hiding on Wangong Mountain in Yixian and then on Sikong Mountain in southwestern Anhui. Thereafter, for ten years he wandered with no fixed abode.
Daoxin
He met Daoxin, (580-651) a novice monk of just fourteen, in 592. Daoxin attended Sengcan for nine years and received Dharma transmission when he was still in his early twenties.
Subsequently, Sengcan spent two years at Mount Luofu (Lo-fu shan, northeast of Kung-tung (Canton)) before returning to Wangong Mountain. He died sitting under a tree before a Dharma assembly in 606.
Dumoulin notes that a Chinese official, Li Ch’ang found Sengcan's grave in Shu-chou in 745 or 746.
Sengcan received the honorary title Jianzhi 鑑智 (“Mirror Wisdom”) from the Tang dynasty emperor Xuan Zong.