成唯識論演祕 6.407

6.407

詳曰：此文定據同時而明，何惑致問繁乎翰墨，前後相望前已說故。又問同聚異體尚說互作等無間緣，同體四分除相餘，三體既是一，一開導時餘亦開導，何不許三前後互望為等無間？此義應思。

We comment: This passage is definitely explained based on simultaneity. Why raise a question in confusion and multiply words? For regarding prior and posterior in relation to each other, it was already explained previously. Furthermore, it is asked: If those that are concomitant but of different substances are still said to mutually serve as equal-and-immediate conditions, then regarding the four parts of the same substance, excluding the nimitta-bhāga, since the substances of the remaining three are one, when one opens the way and guides, the others also open the way and guide; why not allow the three, mutually viewed prior and posterior, to serve as equal-and-immediate conditions? This meaning should be reflected upon.