瑜伽論記 5.476

5.476

謂佛尊若不棄捨諸壽行等者，此有二說：一云，佛壽百年，但年八十捨第五分，二十年為一分壽故，經多說迦葉佛二萬歲時出，釋迦佛人壽百歲時出；二云，釋迦佛大分應壽百二十歲，四十年為一分，但年八十捨第三分壽，諸教多言此四十人壽一百二十五歲，東洲二百五十等。准大集經後解為勝，彼說佛壽為三分故，壽行命有何差別，壽是限量經時久近義，命是活義，壽命即行，佛顯於有知足，故捨壽行，為顯於命亦得自在，為須跋等却後三月方滅度故留命行，然以所捨餘分所有福業施弟子。

Regarding 'If the Honoured Buddha had not cast off the life-formations and so forth,' there are two explanations: One says that the Buddha's lifespan was one hundred years, but at eighty years he cast off the fifth portion, twenty years constituting one portion of lifespan; for the sūtras mostly state that the Buddha Kāśyapa appeared when human lifespan was twenty thousand years, and the Buddha Śākyamuni appeared when human lifespan was one hundred years. The second says that Śākyamuni Buddha's major portion should have had a lifespan of one hundred and twenty years, with forty years constituting one portion, but at age eighty he cast off the third portion of his lifespan; many teachings say that in this [age] human lifespan is one hundred and twenty-five years, in the eastern continent it is two hundred and fifty, and so forth. According to the Mahāsaṃnipātasūtra, the latter explanation is superior, for it says the Buddha's lifespan has three portions. What is the distinction between life-formations (āyuḥsaṃskāra) and vitality (jīvita)? Lifespan (āyus) has the meaning of a measured limit of elapsed time, long or short; vitality (jīvita) has the meaning of living. Both lifespan and vitality are formations. The Buddha, to show contentment regarding existence, cast off his life-formations; and to show that he had also attained mastery over vitality, for the sake of Subhadra and others he postponed parinirvāṇa for three months, thereby retaining the vitality-formations; however, he gave the merit of the remaining portion that he relinquished to his disciples.