大乘起信論義記 2.208

2.208

第二能見相，即是轉相，依前業相轉成能見，故言以依動故能見；若依性淨門，則無能見，故云不動則無見，反顯能見必依動義。如是轉相雖有能緣，以境界微細故猶未辨之。如《攝論》云「意識緣三世境及非三世境是則可知，此識所緣境不可知故。」既云所緣不可知，即約能緣以明本識轉相義也。

The second, the mark of the perceiver, is the evolving mark. Relying on the preceding karmic mark, it evolves into the perceiver; hence it says “because it is dependent on agitation, there is perceiving.” If one relies on the gate of intrinsic purity, there is no perceiver; hence it says “if unmoved, there is no seeing,” which conversely reveals the meaning that perceiving necessarily relies on agitation. Although such an evolving mark has an apprehending subject, because the object of cognition is subtle, it is not yet distinguishable. As the Mahāyānasaṃgraha says: “The mental consciousness cognizing objects of the three times and objects not of the three times is knowable, whereas the object cognized by this consciousness cannot be known.” Since it says that the object cognized cannot be known, this explains the meaning of the evolving mark of the fundamental consciousness in terms of the apprehending subject.