成唯識論述記 7.157

7.157

述曰：謂苦根在五識，由無漏後得智位引，或引後時五識等生，非悔、眠二有此義故。問：憂根雖非無學，二十二根中仍名不斷，何惡作等不如是也？

The Commentary states: This means that the faculty of pain resides in the five consciousnesses and is induced during the state of uncontaminated subsequent wisdom, or induces the subsequent arising of the five consciousnesses and so forth; the two [factors of] regret and torpor do not possess this feature. Question: Although the faculty of sorrow does not belong to one beyond training, among the twenty-two faculties it is still called 'non-abandonment'; why are remorse and so forth not like this?