大般涅槃經義記 7.86

7.86

法中有四：一明涅槃本有非今、二明眾生不見謂無、三明菩薩修道始見、四明雖始見法非今有。初中有二：一明涅槃體非本無，文有反順，「涅槃體非本無今有」是其順也，「若涅槃體本無今有則非無漏常住之法」是其反也。問曰：方便斷結，涅槃本無今有，豈非無漏？釋言：此等實是方便斷結無漏，但非自體本淨無漏，故云非也。二「有佛」下明其常有，約佛顯之。隨相論之，有佛成道證會始有，無佛證會涅槃則無，實則涅槃古今不變，故曰常住。此初段竟，後三可知。

Within the dharma there are four [points]: first, clarifying that nirvāṇa is originally existent and not newly arisen; second, clarifying that sentient beings do not see it and deem it non-existent; third, clarifying that bodhisattvas cultivate the path and begin to see it; fourth, clarifying that although it is newly seen, the dharma is not newly existent. Within the first there are two: first, clarifying that the essence of nirvāṇa was not originally non-existent, the text having the direct and the contrapositive: "the essence of nirvāṇa is not originally non-existent and now existent" is the direct; "if the essence of nirvāṇa were originally non-existent and now existent, then it would not be an untainted, permanently abiding dharma" is the contrapositive. Question: When fetters are severed through expedient means, nirvāṇa was originally non-existent and is now existent; how could this not be untainted? Explanation: These are indeed untainted in the sense of severing fetters through expedient means, but they are not untainted in their own substance as originally pure, and therefore he says "it is not." Second, from "there is a Buddha" downward clarifies that it is permanently existent, revealing it in terms of Buddhas. Discussing it according to marks: when there is a Buddha who attains the path and realizes it, only then does it exist; when there is no Buddha who realizes it, nirvāṇa is absent. Yet in reality, nirvāṇa is unchanging throughout past and present, and is therefore called permanently abiding. This ends the first section; the latter three can be understood.