成唯識論述記 3.222

3.222

述曰：下釋頌意，此四分中，相、見名外，見緣外故；三、四名內，證自體故，唯見分有種種差別，或量、非量。既言見分或非、比故，別立第四，此唯眾生四分，故言纏縛相及麁重二縛具故，無漏心等雖有四分，而非纏縛。問：如諸佛及因五、八識等唯現量者，應但三分，見分即得，為三果故。答：此不然，外、內定故，見分緣外、用外也，不得復為緣內果故；一心見分用，不得通緣內、外法故。雖緣真如，真如非外，以見分用外故，亦不得緣。若爾，內心應非外果，此義如量，義准可知。

The Commentary states: Below, it explains the verse's meaning. Among these four parts, the nimittabhāga and darśanabhāga are called external because the darśanabhāga cognizes what is external; the third and fourth are called internal because they realize their own entity. Only the darśanabhāga has various differentiations, being either a valid or an invalid cognition. Since it is said that the darśanabhāga may be an invalid cognition or an inference, a fourth part is separately established. This applies only to the four parts of sentient beings; hence it speaks of being entwined, because they possess both the bondage of marks and the bondage of coarse heaviness (dauṣṭhulya). Although the untainted mind and so on possess the four parts, they are not entwined. Question: In the case of Buddhas, as well as the five and eighth consciousnesses on the causal stage, which are exclusively direct perception, there should be only three parts, because the darśanabhāga would be able to serve as the result of the third. Answer: This is not so. Because the external and internal are fixed, the darśanabhāga cognizes the external and its function is external, so it cannot further serve as the result of cognizing the internal; for the function of the darśanabhāga within a single mind cannot extend to cognizing both internal and external phenomena. Even when it cognizes tathatā, tathatā is not external; yet because the function of the darśanabhāga is directed externally, it also cannot cognize [inwardly as a result]. If so, the internal mind should not be the result of the external; this meaning is in accordance with valid cognition, and can be inferred accordingly.