As with all the early Chan patriarchs, many of the details of Hongren’s life are uncertain and much of his biography is layered with legend added well after his death.

[2] At the age of either seven or twelve, Hongren left home to become a monk and began his studies under Daoxin, who, according to tradition, immediately recognized his insight: The Ch’üan fa pao chi (Annals of the Transmission of the Dharma-treasure), written approximately 712, says that Hongren was quiet and withdrawn, diligent in his menial labors, and sat in meditation throughout the night.

[6] According to the Treatise on the Essentials of Cultivating the Mind, Hongren's basic teaching was that the Pure Mind was obscured by “discriminating thinking, false thoughts, and ascriptive views.”[7] Eliminating false thoughts and maintaining a constant awareness of one’s natural enlightenment ensures Nirvana naturally arises.

"[8] The Chinese character for "one" is a single horizontal line, resembling a horizon, and metaphorically represents the unity of the mind and Buddha nature.

He also taught that the meditator should observe the mental processes within: "View your own consciousness tranquilly and attentively, so that you can see how it is always moving, like flowing water or a glittering mirage.

"[9] Hongren was held in high esteem by later Chan-adepts in the ancient capital cities of Chang'an and Luoyang in the early eighth century, when Chan moved from a rural base to the centre of Chinese power, in the major urban areas and the imperial court.