The Dunwu rudao yaomen lun (Treatise on the Essential Doctrine of Suddenly Entering into Enlightenment) is attributed to him.
[3] According to Dazhu Huihai's entry in the Jingde Chuandenglu, his preceptor was Daozhi of the Dayunsi in Yuezhou (Zhejiang).
According to Jinhua Jia, this suggests that Dazhu was either the most senior or most important of Mazu's disciples.
He later said of this encounter with Mazu: “I, the poor priest, heard that the Reverend in Jiangxi said, ‘Your own treasure is perfectly complete; you are free to use it and do not need to seek outside.’ From that moment onward, I have ceased [from my seeking].”[1] Dazhu is said to have later composed the Dunwu rudao yaomen lun at his home monastery in Yuezhou.
The Dunwu rudao yaomen lun, attributed to Dazhu Huihai, describes the mind in the following terms: Mind has no colour, such as green or yellow, red or white; it is not long or short; it does not vanish or appear; it is free from purity and impurity alike; and its duration is eternal.
"[8] According to Dazhu, when we encounter objects, the things being looked at do not actually exist within the sphere of perception.
[9] When asked if it was still possible to perceive even while nothing confronts us, Dazhu responds in the affirmative, saying: We are now talking of that perception which is independent of there being an object or not.
"[12] In the Dunwu rudao yaomen lun, Dazhu says that dhāyna is perpetual and not affected by speech or silence, stating that dhyāna functions even when we are engaged in speaking or making distinctions.
[14] Dazhu defines wisdom as being able to distinguish "every sort of good and evil," while dhyāna means to be unaffected by love or aversion even while making these distinctions.
[17] An important theme of the Dunwu rudao yaomen lun is non-dwelling (or non-abiding, wuzhu), which Dazhu defines as not being fixed on good or evil, being or non-being, inside or outside (or somewhere in between), void or non-void, as well as on concentration or distraction.
Dazhu describes this negatively as a "craze for karmic activities," saying it is no different from pursuing sounds and forms.
Instead, Dazhu advises his audience to "desist from it all" and says that being an unconcerned person means not to follow sights and sounds so that they stir the mind.
[24]The Dunwu rudao yaomen lun usually occurs together with a second text appended to it called the Zhufang menren canwen yulu (Record of Questions Asked by Disciples from Everywhere), also attributed to Dazhu, and the two texts together make up the Dunwu yaomen (Essential Gate of Immediate Enlightenment).
[26] According to Poceski, the format and doctrines of the Dunwu rudao yaomen lun mark it as a transitional text between early and classical Chan.