觀彌勒上生兜率天經贊 2.131

2.131

贊曰：第三、明下生時節。即住彼天之壽量也。梵云瞻部，此樹名也。言閻浮提，訛耳。此洲從樹為名，四洲所由如餘處辨。此間四百歲當彼天中一日一夜，類彼三十日為一月、十二月為一年，彼天壽四千歲，慈氏窮彼天壽而方下生，不中夭故。此經云當閻浮提五十六億萬歲者，依《瑜伽論》第四及《立世經》、《毘婆沙》等計。此間四百歲為彼一日，此四千歲為彼十日，此間四萬歲為彼百日。彼天一年當此一十四萬四千歲，彼天十年當此一百四十四萬歲，彼天百年當此一百四十四億歲，彼天千年當此一千四百四十億歲，彼天四千歲當此五千七百六十億歲，即與經文不同。今以理推，初以人間四百年為彼一日一夜，復若數以一百而為一類數，計即相當。一當百故，人間四十歲為彼十日，人間四百歲為彼百日，人間一千四百四十歲為彼一年，人間一萬四千四百歲為彼十年，人間一億四萬四千歲為彼百年，人間十四億四萬歲為彼千年，彼四千年當人間五十七億六萬歲。西方有三億數：一、十萬為億；二、百萬為億；三、千萬為億。以理推排，以千萬為一億計之，即相當矣。是故於經億字之上應加七字，其前六字應萬上安。只恐梵本誦有參差過，譯家自成謬。若不爾，便少一億五萬歲。理定應爾，智者應知。然此歲數，四文不同。《賢劫定意經》云「彌勒五億七千六萬歲當下作佛」，其五億者即五十億，前以千萬為一億成五十億，此以萬萬為一億故成五億，七十萬者即七億也。十萬為一億故六萬數同，更不勞釋。唯此一經，增減雖殊、與論算同，自餘皆別。雙卷《泥洹經》云「一億四千歲」，全不相當。此經及《一切智光明仙人慈心經》云「五十六億萬歲」，如前已正。《菩薩處胎經》及《賢愚經》云「五十六億七千萬歲」，其六字應云七，其七字應云六。其千萬者，以百萬為一億以算之，六千萬者六十億也，義不相違。如是推尋雖乖古疏，尋文究理亦應無謬。菩薩在天壽量曾無中夭，生在人間。《大成佛經》說：壽六萬歲，天盡其年。人間長者，時宜現故。不同釋迦大盡其年，人間早滅，眾生厭故、化緣畢故。《處胎經》說：彌勒人間壽八萬四千歲。若依彼說，不須和會。如《下生經》陳下生事，天利既畢、人機復熟，故乃下生。

The commentary says: Third, explaining the time of the descent to birth—that is, the lifespan while dwelling in that heaven. In Sanskrit it is called Jambu, which is the name of a tree; saying 'Yanfutid' (Jambudvīpa) is merely a corruption. This continent is named after the tree; the origins of the four continents are as explained elsewhere. Four hundred years here corresponds to one day and one night in that heaven; thirty of their days make one month, and twelve months make one year. The lifespan in that heaven is four thousand years. Maitreya exhausts the lifespan of that heaven and only then descends to be born, because he does not die prematurely. When this sūtra says 'fifty-six hundred million years of Jambudvīpa,' it is calculated according to the fourth fascicle of the Yogācārabhūmi, the Sūtra on the Establishment of the World, the Vibhāṣā, and others. Four hundred years here makes one day there; four thousand years here makes ten days there; forty thousand years here makes one hundred days there. One year of that heaven corresponds to one hundred and forty-four thousand years here; ten years of that heaven corresponds to one million four hundred and forty thousand years here; one hundred years of that heaven corresponds to one hundred and forty-four hundred million years here; one thousand years of that heaven corresponds to one thousand four hundred and forty hundred million years here; four thousand years of that heaven corresponds to five thousand seven hundred and sixty hundred million years here. This differs from the sūtra text. Now, reasoning through it, first four hundred human years makes one day and one night there; further, if one calculates in units of one hundred, the count then corresponds. Because one corresponds to one hundred: forty human years makes ten days there; four hundred human years makes one hundred days there; one thousand four hundred and forty human years makes one year there; fourteen thousand four hundred human years makes ten years there; one hundred million forty-four thousand human years makes one hundred years there; fourteen hundred million forty thousand human years makes one thousand years there; four thousand years there corresponds to fifty-seven hundred million sixty thousand human years. In the Western regions there are three reckonings of 'hundred million' (koṭi/ayuta): first, one hundred thousand is a koṭi; second, one million is a koṭi; third, ten million is a koṭi. Reasoning through it, if one calculates with ten million as one hundred million, it then corresponds. Therefore, above the character 'hundred million' in the sūtra, the character 'seven' should be added, and the preceding character 'six' should be placed above 'ten thousand'. One only fears that there was an error of discrepancy in the recitation of the Sanskrit manuscript, or the translators themselves made a mistake. If it were not so, it would fall short by one hundred million fifty thousand years. In principle it definitely must be so; the wise should know this. However, regarding this number of years, four texts differ. The Xianjie dingyi jing says: 'Maitreya will descend to become a Buddha in five hundred million seventy-six thousand years.' Its 'five hundred million' is precisely fifty hundred million: previously, taking ten million as one hundred million made fifty hundred million; here, taking one hundred million as one hundred million makes five hundred million; and 'seventy ten-thousand' is precisely seven hundred million. Because one hundred thousand is one hundred million, the number 'six ten-thousand' is the same, so there is no need to explain it further. Only in this single sūtra, though the additions and subtractions differ, does it agree with the treatise's calculation; all the rest are different. The two-fascicle Nirvāṇa Sūtra says 'one hundred million four thousand years,' which does not correspond at all. This sūtra and the Sūtra on the Compassionate Mind of the Omniscient Radiant Sage say 'fifty-six hundred million ten-thousand years,' which has already been corrected above. The Sūtra on the Bodhisattva Dwelling in the Womb and the Sūtra of the Wise and the Foolish say 'fifty-six hundred million seventy million years'; its character 'six' should be 'seven', and its character 'seven' should be 'six'. As for its 'ten million', if one calculates taking one million as one hundred million, 'sixty million' is sixty hundred million, and the meaning is not contradictory. Investigating in this manner, although it departs from ancient commentaries, examining the text and investigating the principle should also be free of error. The bodhisattva's lifespan in heaven is never cut short prematurely; he is then born among humans. The Great Sūtra on Attaining Buddhahood says: his lifespan is sixty thousand years, and he fully completes his heavenly years. His lifespan among humans is long because it is fitting to manifest so at that time. It is not like Śākyamuni, who largely completed his heavenly years, but passed away early in the human realm because sentient beings grew weary and his causes for transformation were finished. The Sūtra on Dwelling in the Womb says: Maitreya's lifespan among humans is eighty-four thousand years. If one relies on that statement, no harmonization is needed. As the Sūtra on the Descent to Birth states regarding the events of his descent to birth, when the benefit for the devas is completed and the capacity of humans is mature, he then descends to be born.