三彌勒經疏 1.163

1.163

經曰「爾時彌勒菩薩」以下，第二答佛問，謂辨彌勒成佛時正報身也。汎論諸佛，皆有八相：一上天、二入胎、三住胎、四出胎、五出家、六成道、七說法、八滅度。今此經中有四：一入胎、二出胎、三出家、四成道。是初也。准諸經論，菩薩住天將下生時，先觀四事：一觀時分，謂何時中應出世，即知人壽八萬歲乃至百歲等也。二觀處所，謂何方處應出世，即出閻浮提中印度也。三觀種性，謂出剎利或波羅門姓。四觀依器，謂出父母。觀此四事已，後七日下閻浮提，生中印度也。今此中言父母者，顯觀依器。《大成佛經》云「佛雖在胎，如遊天堂」也。

From the sūtra's words 'At that time Maitreya Bodhisattva' onward, this is the second [part], answering the Buddha's question, which explains the primary fruition body when Maitreya attains Buddhahood. Generally speaking, all buddhas have eight aspects: first, ascending to heaven; second, entering the womb; third, dwelling in the womb; fourth, emerging from the womb; fifth, going forth into homelessness; sixth, attaining awakening; seventh, turning the wheel of the Dharma; eighth, passing into extinction. Now, in this sūtra there are four: first, entering the womb; second, emerging from the womb; third, going forth into homelessness; fourth, attaining awakening. This is the first. According to various sūtras and treatises, when a bodhisattva residing in heaven is about to descend and be born, he first observes four matters: First, he observes the time: in what era he ought to appear in the world, knowing whether human lifespan is eighty thousand years down to one hundred years, and so forth. Second, he observes the place: in which region and location he ought to appear in the world, namely being born in Jambudvīpa, in Central India. Third, he observes the clan: whether he will be born into the kṣatriya or the brāhmaṇa clan. Fourth, he observes the supportive vessel: namely, being born to his parents. Having observed these four matters, after seven days he descends to Jambudvīpa and is born in Central India. Now, speaking here of the parents demonstrates the observation of the supportive vessel. The Great Attainment of Buddhahood Sūtra says: 'Although the Buddha was in the womb, it was as if he were wandering through a celestial palace.'