大般涅槃經義記 1.230

1.230

第四如來述讚之中，初對向前雖知如來方便涅槃而為讚歎。「善哉」歎詞。「能知」已下，出其所歎。「汝今」已下，對前不能不懷苦惱而為開解。於中有三：一明如來化必須滅；二「不應思」下，明佛壽命長短難測，不應愁惱；三「一切法」下，明佛於有心不染著，令求捨離，不應愁惱。初中先喻，「如娑羅娑鳥」，喻佛應身；「春陽月」者，是養子月，喻諸眾生道機熟時；「皆共集彼阿耨池」者，喻佛同歸盡滅大池；鳥入大池，引子同入，佛入涅槃，為引眾生趣入無為。下次合之，「諸佛亦爾」，合娑羅娑鳥。「皆至是處」，合春陽月，集阿耨池，所謂至於盡滅之處。第二句中，「不應思佛長壽、短壽」，以理誡勸長短難測，故不應思。第三句中，「一切諸法皆如幻」者，明有虛妄。「如來在中以方便力無所染著」，明佛不染。在而不著，故曰方便。「何以」下，釋諸佛於有法皆不染，故曰法爾。以不著故，今入涅槃，不應愁惱。

In the fourth [part], the Tathāgata's praise and affirmation: first, in response to the previous 'although knowing the Tathāgata enters the nirvāṇa of expedient means', he offers praise. "Excellent!" is an exclamation of praise. From "being able to know..." downward, he expresses what he praises. From "you now..." downward, in response to the previous 'cannot help but harbor distress', he provides opening and understanding. Within this there are three parts: 1. Explaining that the Tathāgata's transformation must cease; 2. From "you should not think..." downward, explaining that the length of the Buddha's lifespan is difficult to fathom, so one should not grieve; 3. From "all dharmas..." downward, explaining that the Buddha's mind is unattached to existence, causing them to seek abandonment of it, so one should not grieve. In the first part, the simile is given first: "like the sārasa birds" illustrates the Buddha's responsive body; "the spring sun month" is the month for rearing young, illustrating the time when sentient beings' capacity for the Way is mature; "all gather together at that Anavatapta Lake" illustrates the Buddha's return to the great lake of complete extinction; when the birds enter the great lake, they lead their young to enter as well, and when the Buddha enters nirvāṇa, it is to lead sentient beings to enter the unconditioned. Next, the application matches it: "all buddhas are also like this" matches the sārasa birds; "all reach this place" matches gathering at Lake Anavatapta in the spring sun month, which refers to reaching the place of complete extinction. In the second clause, "you should not think of the Buddha's long life or short life", by means of principle he admonishes and advises that the length is difficult to fathom, hence one should not ponder it. In the third clause, "all dharmas are like an illusion" explains that existence is false. "The Tathāgata, being among them, by the power of expedient means is without attachment" explains that the Buddha is untainted. Being present yet unattached is therefore called 'expedient means'. From "why..." downward explains that it is the natural law for all buddhas to be unattached to conditioned dharmas, hence he says 'natural law'. Because he is unattached, he now enters nirvāṇa, and one should not grieve.