金剛經纂要刊定記 1.101

1.101

梵語提婆盤豆，此云天親，是地前四加行位菩薩，即無著弟也。無著，梵語阿僧佉，是初地菩薩，即天親兄也。補處即彌勒菩薩，見在兜率天上次補佛處，號曰當來下生彌勒尊佛。以二菩薩依稟彌勒菩薩偈頌，造論解經，故云師補處尊。下懸談廣明。

In Sanskrit, Devabandhu, translated here as Vasubandhu (Tianqin), was a bodhisattva of the four aids to penetration stages prior to the bhūmis, namely the younger brother of Asaṅga. Asaṅga, in Sanskrit Asaṅga (Asengqie), was a bodhisattva of the first bhūmi, namely the elder brother of Vasubandhu. The "Successor" is Maitreya Bodhisattva, currently in the Tuṣita heaven, next in succession to fill the Buddha's place, titled the Future Descending Venerable Buddha Maitreya. Because the two bodhisattvas relied upon and received Maitreya Bodhisattva's verses to compose treatises explaining the sūtra, it is said that they "took the Venerable Successor as teacher." This will be explained extensively below in the introductory discussion.