大般涅槃經集解 62.10

62.10

案僧亮曰：說緣因性，眾生必得，故名有也。相續不異，即如來也。僧宗曰：第三，出佛性體也。寶亮曰：第四，歷緣因。四無量行即是緣因，善菩薩常行，如影隨形也。佛性名如來者，行四無量，近得初住一子之地，遠則圓滿得佛，故名如來也。

Sengliang comments: "Speaking of the nature of conditioning causes: sentient beings will definitely attain it, and therefore it is called existent. Continuing without difference, it is none other than the Tathāgata." Sengzong says: "Third, this brings out the substance of buddhadhātu." Baoliang says: "Fourth, this examines conditioning causes. The practices of the four immeasurables are precisely the conditioning causes; a good bodhisattva constantly practices them, like a shadow following a form. That buddhadhātu is called the Tathāgata: by practicing the four immeasurables, closely one attains the stage of viewing sentient beings as an only child at the first dwelling, and distantly one attains the full perfection of buddhahood; therefore it is called the Tathāgata."