成唯識論演祕 1.663

1.663

答：業等合時有所依，實而是常故，故得通常，離即不爾，故不相例。又雖待因體非所作，故得為常。餘皆准此。

Answer: When action and so forth conjoin, they have an inhering basis, and since the substance is eternal, [conjunction] can be common [to the eternal and impermanent]; disjunction is not like that, so they are not analogous. Furthermore, although it depends on causes, its essence is not produced, so it can be eternal. The rest are all understood by analogy with this.