成唯識論演祕 4.630

4.630

論云：問：如世尊說過、未諸行為緣生意，過、未非有，何故說彼為緣生意？若意亦緣，非有事境，云何佛說由二種緣，諸識得生？答：由執持諸五識身所不行義，故佛世尊假說名法。是故說言緣意及法，意識得生。

The Treatise says: Question: As the World-Honoured One said that past and future saṃskāras serve as conditions to generate mental consciousness, since past and future do not exist, why say that they serve as conditions to generate mental consciousness? If the manas also takes nonexistent entities and objects as its condition, how could the Buddha say that based on two kinds of conditions, the consciousnesses arise? Answer: Because it grasps and maintains referents not functioning for the group of five consciousnesses, the Buddha, the World-Honoured One, metaphorically designated them as dharmas. Therefore, it is said that conditioned by the manas and dharmas, mental consciousness arises.