大般涅槃經義記 2.107

2.107

第二段中迦葉先請，下佛為解，有四復次：前二復次明常所以、後二復次顯常殊勝。就前二中，初一明其諸命同入所以名常，先喻，後合。「人中、天上、地及虛空悉入如來壽命海」者，解有二義：一就自行趣果以論，佛在因中具有無量人天善業，齊應得果，今皆共感如來之命，是以云入；二約他以辯，一切人天所有壽命皆在如來壽命限中，故說為入。第二明其出生多命故得為常，於中先喻，「阿耨達池」從主立稱，此方正翻名無熱惱，傍名清涼，無熱惱龍居其中故。「出四河」者，經說不定，或云出八、或復言出二十大河，各有所以。言出四者，此池在於香山之頂，於山四面有四獸頭：東方金象口出恒河、南方銀牛口中流出辛頭大河、西瑠璃馬口中流出悉陀大河、北頗梨師子口中流出愽叉大河。言二十者，如《阿含》說「四河去池四十里外各出四河，通本二十，隨方赴海。」言出八者，佛出山東，東方五河人皆具見，備取為喻，餘方大河有大名聲，人皆同知，亦取為喻，通前說八；餘方小河無大名聲，人多不知，故不舉之，所以言八。今但云四。下次合之，「如來亦爾，出一切命」，解有兩義：一就自己化用以論，化起多命，名出一切；二就如來化他以說，教他令得，是故云出。後二復次明常勝中，前明法常、後顯報常，並先立喻，後合可知。

In the second section, Kāśyapa first makes a request, and below the Buddha explains it for him in four further points: the first two points explain why [the Buddha] is eternal, and the latter two points reveal the supremacy of this eternity. In the first two, the first one explains why all lifespans merge into one, which is why it is called eternal; it first gives a simile and then applies it. Regarding "those among humans, in the heavens, on earth, and in empty space all enter the ocean of the Tathāgata's lifespan," there are two explanations: First, in terms of one's own practice tending toward the fruit, when the Buddha was on the causal stage, he possessed immeasurable good karma of humans and gods, all of which should equally attain the fruit; now these all jointly evoke the lifespan of the Tathāgata, and therefore it is said to enter. Second, explaining in terms of others, all the lifespans of all humans and gods fall within the bounds of the Tathāgata's lifespan, and hence it is said to enter. The second explains that because it gives rise to many lifespans, it is eternal; within this it first presents a simile. "Lake Anavatapta" takes its name from its master: translated correctly in this land it is called "Free from Heat and Affliction," and an alternative name is "Cool and Clear," because the dragon free from heat and affliction dwells within it. Regarding "emitting four rivers," the sūtras vary: some say it emits eight, and others say it emits twenty great rivers, each with its reason. Saying that it emits four: this lake is on the summit of Gandhamādana Mountain, and on the four sides of the mountain there are four beast heads: from the gold elephant mouth in the east flows the Gaṅgā River; from the silver bull mouth in the south flows the Sindhu River; from the lapis lazuli horse mouth in the west flows the Sītā River; and from the crystal lion mouth in the north flows the Vakṣu River. Saying twenty: as the Āgamas say, "Each of the four rivers, forty li from the lake, produces four rivers; including the originals they are twenty, flowing to the sea according to their directions." Saying eight: the Buddha appeared east of the mountains, and people all saw the five rivers in the east, which were all taken as similes; the great rivers of the other directions had great renown and were known by everyone, so they were also taken as similes, together with the former making eight; the minor rivers of other directions had no great renown and were unknown to most, so they were not mentioned—hence the mention of eight. Now it only says four. Next it is applied: "The Tathāgata is also like this, emitting all lifespans." There are two explanations: First, in terms of his own transformative functioning, transforming and raising many lifespans is called emitting all. Second, in terms of the Tathāgata transforming others, teaching others to obtain them, hence it says "emitting." In the latter two points revealing the supremacy of eternity: the former explains the eternity of dharma, and the latter reveals the eternity of the reward; both first set up similes, and their applications can be known.