大般涅槃經義記 8.244

8.244

自下第二，舉彼佛性是因非果，對顯涅槃是果非因。於中，初言「是因非果名為佛性」略以標舉。下釋其相，先解「非因生故是因非果」明性非是生因家果，「非沙門果故名非果」明性非是了因家果。「何故名因，以了因故」釋是因也。因有二種：一法佛性、二報佛性。如來藏體是法佛性，於此體上有可出生報佛之義，名報佛性。其法佛性望彼涅槃性淨之果，但是了因而非生因，故下文言「涅槃因者所謂佛性」。佛性之性不生涅槃，云何為了？彼如來藏性是真法，研之則明。從本已來有可顯了，成涅槃義，故名了因。如瓶中燈有可見義，瓶破則見。其報佛性望彼菩提方便之果是其生因，從本已來有可出生菩提之義，故名生因。今從初義。是故說言以了因故佛性是因。

From here, the second part adduces that buddha-nature is a cause and not a fruit, in contrast to which it reveals that nirvāṇa is a fruit and not a cause. Therein, the opening words "being a cause and not a fruit is called buddha-nature" briefly introduce it. Below, he explains its characteristics: first, explaining "because it is not produced from a cause, it is a cause and not a fruit" clarifies that the nature is not the fruit of a generative cause; "because it is not the fruit of a śramaṇa, it is called not a fruit" clarifies that the nature is not the fruit of a revelatory cause. "Why is it called a cause? Because of being a revelatory cause" explains that it is a cause. Causes are of two kinds: first, the dharma-buddha-nature; second, the retribution-buddha-nature. The substance of the tathāgatagarbha is the dharma-buddha-nature; upon this substance there is the capacity to give rise to the retribution-buddha, which is called the retribution-buddha-nature. In relation to that fruit of naturally pure nirvāṇa, its dharma-buddha-nature is only a revelatory cause and not a generative cause; therefore, a later passage states: "The cause of nirvāṇa is what is called buddha-nature." The nature of buddha-nature does not generate nirvāṇa; how is it revelatory? That nature of the tathāgatagarbha is the true dharma; when refined, it becomes luminous. From the beginning, it has possessed the capacity to be revealed and accomplish the meaning of nirvāṇa, hence it is called a revelatory cause—just as a lamp in a jar has the property of being visible, and when the jar is broken, it is seen. In relation to that fruit of expedient bodhi, its retribution-buddha-nature is its generative cause; from the beginning, it has possessed the capacity to give rise to bodhi, hence it is called a generative cause. Here it follows the first meaning; therefore, it is said that because of being a revelatory cause, buddha-nature is a cause.