金光明經玄義 2.15

2.15

次觀心三涅槃金光明者，諦觀心性本來寂滅，不染不淨，染故名生、淨故名滅，生滅不能毀故常、不能染故淨、不能礙故我、不能受故樂，是為性淨涅槃。若妄念心起，悉以正觀觀之，令此正觀與法性相應，妄念不能染、不能毀、不能礙、不能受。常樂我淨者，即是圓淨涅槃。又以正觀觀諸心數心數法不行，心數法不能毀、不能染、不能礙、不能受者，名方便淨涅槃。是名觀心三涅槃金光明。六即如前。

Next, regarding observing the mind as the Suvarṇaprabhāsa of the three kinds of nirvāṇa: attentively observing the mind-nature as fundamentally quiescent, neither defiled nor pure—defilement is called arising, and purity is called cessation; because arising and cessation cannot destroy it, it is permanent; because it cannot be defiled, it is pure; because it cannot be obstructed, it is the self; because it cannot experience [duḥkha], it is bliss—this is the inherently pure nirvāṇa. If stray thoughts arise, one observes them all with correct contemplation, causing this correct contemplation to accord with the dharmatā so that stray thoughts cannot defile, cannot destroy, cannot obstruct, and cannot be experienced [as duḥkha]. Permanence, bliss, self, and purity in this sense is the completely pure nirvāṇa. Furthermore, observing all mental factors with correct contemplation so that the factors of mental events do not operate, and the factors of mental events cannot destroy, cannot defile, cannot obstruct, and cannot be experienced [as duḥkha], is called the expedience-pure nirvāṇa. This is called observing the mind as the Suvarṇaprabhāsa of the three kinds of nirvāṇa. The six identities are as before.