大般涅槃經義記 2.124

2.124

上來第一明佛體常即是自德，自下第二就常說歸明攝他德。於中有三：一就常辯歸、二迦葉聞說領解修行、三如來述讚。初中「應修佛、法及僧而作常想」，總勸修學。亦應說言作無異想及無變想，但今文中乘上所辯但勸修常，餘略不論。「是三法」下別教修學，先開三門、次廣辯釋。「若言如來異法僧」下破邪顯正。前開門中言「是三法無異想」者明非別體，一佛體上隨義分三，故無別異；「無無常」者，體非生滅，不同變易；「無變異」者，體無終盡。不同分段，准釋應爾。約此三門，教除邪想。

Above, the first [part] explained that the permanence of the Buddha's essence is his own virtue; from here on, the second [part] discusses taking refuge in terms of permanence, explaining that he gathers in the virtues of others. Within this there are three parts: first, distinguishing refuge in terms of permanence; second, Kāśyapa hears the teaching, comprehends it, and practices it; third, the Tathāgata narrates and praises it. In the first part, "One should cultivate the Buddha, the Dharma, and the Saṅgha, forming the thought of permanence" generally exhorts practice and study. One should also say to form the thought of non-differentiation and the thought of non-alteration, but in the present text, following on from what was discussed above, he only exhorts cultivating permanence, leaving the rest unaddressed for brevity. From "These three dharmas..." onwards, he specifically teaches practice and study: first opening three gates, and next elaborating and explaining them. From "If one says that the Tathāgata is different from the Dharma and Saṅgha..." onwards, he refutes the heterodox and reveals the orthodox. In the previous opening of the gates, saying "These three dharmas have no thought of differentiation" clarifies that they are not separate essences: based on the single Buddha essence, three are distinguished according to meaning, and therefore there is no differentiation; "have no impermanence" means that the essence is not production and cessation, not being identical to changeful [transmigration]; "have no alteration" means that the essence has no end or exhaustion, not being identical to portioned [transmigration]—judging by the explanation, it should be so. Relying on these three gates, he teaches the elimination of erroneous thoughts.