成唯識論述記 1.674

1.674

述曰：若遮時，無表故；若表時，無遮故。此二相違，如何言一？汝之表、遮，應非體一；相相違故；如水、火等。又此言表，即同第一；若言遮者，即同第二。

The Commentary states: When there is exclusion, there is no affirmation; when there is affirmation, there is no exclusion. These two being contradictory, how can you say they are one? "Your affirmation and exclusion should not be of one substance; because their marks are mutually contradictory; like water and fire, and so on." Furthermore, if this word is affirmative, it is identical with the first; if it is exclusionary, it is identical with the second.