Vô Ngôn Thông

Vô Ngôn Thông (d. 826), whose name means "Wordless Understanding," was a Chinese Buddhist monk who founded the second major Thiền school in Vietnam. Born around 759 CE in Guangzhou, he trained under the great Tang dynasty Chan master Baizhang Huaihai, one of the most important figures in Chinese Chan, who established the first independent monastic code for Chan communities. The Vô Ngôn Thông school thus carried the imprint of Baizhang's transformative vision and was associated with the Hongzhou school of Mazu Daoyi.

According to tradition, Vô Ngôn Thông attained enlightenment upon hearing Baizhang say: "If the mind is pure and empty, the sun of wisdom will shine by itself." Around 820 CE, he traveled to Annam (present-day northern Vietnam) and took up residence at Kiến Sơ Temple in Phù Đổng village. Following Bodhidharma's example, he practiced "wall-gazing" meditation, sitting silently for extended periods. Before his death in 826, he transmitted his "Buddha-heart seal" to Cảm Thành, who became the second patriarch. The school flourished for centuries, becoming one of the three major Thiền traditions that Emperor Trần Nhân Tông would later synthesize into the unified Trúc Lâm school.