大般涅槃經疏 5.6

5.6

Third, at that time Cunda received and understood. Again there are two parts: first, receiving and understanding; second, validating and confirming. Regarding receiving and understanding: although he knew of non-cessation, he could not help but grieve, and could not help but make the request. Although he knew the Tathāgata ceases and yet does not cease, he could not help but rejoice, and could not help but feel pleasure. Validating and confirming also has two parts: first, validating that he cannot help but rejoice; second, stopping him from not being able to help grieving. First, regarding joy: since you are already able to know the Tathāgata's expedient means, you should also know the Tathāgata's reality; therefore, he adduced the two birds to illustrate that the provisional and real cannot be separated. The season of spring warmth illustrates properly suiting the capacities; the pool free from burning heat illustrates nirvāṇa's ease and fearlessness. All Buddhas equally use the two dharmas to respond to conditions without obstruction and with ease; to be able to understand like this: excellent, excellent! Next, from "You should not now ponder long life or short life" onward, four points are adduced in total to stop him from being unable to help grieving. First, adducing the Tathāgata's realm as beyond thought: whether long or short, all are like an illusion; illusory length and illusory shortness are neither short nor long—what is there to grieve over? Second, adducing the Tathāgata's expedient means: whether long or short, the Tathāgata is completely undefiled and unattached within them—what is there to grieve over? Third, adducing the Tathāgata's nirvāṇa: it brings about your cause of giving and attains the immovable fruit; cause and fruit being complete, what is there to grieve over? Fourth, "I serve as a fertile field to bring about your cause and fruit; when you attain cause and fruit, you yourself are a fertile field, and can further bring other people's causes and fruits to fullness; benefiting oneself and benefiting others, what is there to grieve over?" This can be seen by examining the text.