Acharya Dayu, a native of Wuhan surnamed Li, had the secular name Shubei. He served in government during the period of warlord division. Witnessing the warlords contending for supremacy and kingship, seizing territory, slaughtering one another, plundering the people's wealth, and heedlessly leaving the nation in peril and its people in misery, he was filled with grief and indignation. He therefore resolutely abandoned office and left, eventually becoming a monastic at Donglin Monastery on Mount Lu.

He first practiced the Pure Land Dharma gate. Later, while worshipping before the sūtras, he fell gravely ill and nearly died; then he encountered bandits and again nearly died. Although he repeatedly suffered such hardships, he never slackened in the least.

Later, feeling that human life is brief and the Buddhadharma difficult to encounter, he applied himself vigorously to the practice of the Pratyutpanna Samādhi, translated as the “Buddha-Standing Samādhi.” Each period of practice lasted seven or nine days, during which one walked continuously day and night and was not permitted to sit or lie down. Through it, one could perceive the Buddhas of the ten directions standing before one in empty space.

After three or five days, both his legs became swollen, making it difficult for him to move even a single step. Determined to carry through his original resolve and never retreat, the Master gritted his teeth and crawled forward with his hands. After another day or two, his hands too became swollen. Every further advance required immense and arduous effort; the suffering involved was truly more than ordinary people could endure.

For this reason, very few modern Pure Land practitioners cultivated this samādhi; even those who did were unable to persist to the end. When the Master had exhausted his strength and could no longer crawl, he vowed that only death would make him stop. He rolled himself forward, and after this extraordinarily arduous struggle, his grasping mind utterly died away. He entered deeply and silently into great samādhi, where Samantabhadra Bodhisattva appeared, conferred empowerment upon him, and transmitted the Heart-of-Heart Esoteric Dharma.

Samantabhadra also told him that this Dharma was originally contained in the Buddhist canon, that it was highly skillful, and that he could search for it and study it. The Master searched and indeed found it. He then cultivated according to the transmission bestowed by the Bodhisattva and the six mudrās and one mantra described in The Buddha-Heart Sūtra, Also Corresponding to the Great Wish-Fulfilling Dhāraṇī, an esoteric ritual manual in two fascicles translated by Bodhiruci of the Tang dynasty. After seven years of ascetic practice, he attained realization and descended the mountain, opening the Mind-Seal Dharma gate. He became the first patriarch of the Mind-Seal school.

After descending the mountain, in order to let the world know of this skillful and expedient Dharma gate, he displayed a few spiritual powers wherever he went. The regions north and south of the Yangtze were all stirred by this, and at that time no fewer than fifty or sixty thousand people sought the Dharma from him, while nearly two hundred became his close disciples. Later, because his many followers valued spiritual powers but not the Way, the Master changed his appearance and withdrew into seclusion in Chengdu, Sichuan. He instructed Elder Lay Practitioner Wang Xianglu, a disciple who had obtained the heart-essence of his teaching, to succeed to the Dharma and transmit the Way. Later generations honored Wang as the second patriarch of the Mind-Seal school.

Around the 1950s, the Master left a poem at the home of one of his disciples in Chengdu:

How is the flower held up transmitted? It may well be both Esoteric and Chan;

Withdraw into seclusion between the raising of the brows; meet at the edge of a blink.

For one lifetime, follow the ancient oar; lie crosswise through the three realms at will.

At departure, no words remain; take care—one sound: “yuan.”

He placed it among the inkstones and departed without farewell; to this day, no one knows where he ended up. In teaching the Dharma, the Master valued direct pointing to the essential mind and did not establish words and letters. Of the writings he left to later generations, apart from the Song of Liberation written in his early years, only this farewell poem remains.

(Note: “○” is pronounced the same as yuan, “round” or “complete.”)