大乘起信論義記 3.389

3.389

In showing what is right: the words 'free from marks of perception and there is nowhere they do not pervade' explain that because they lack deluded perception, there is nothing they do not perceive. The words 'because their minds are true and real, they are the very nature of all dharmas' mean: the Buddha's mind is free from delusion, its essence is the single source of the mind, and it has no difference of incipient enlightenment; therefore it is called 'true and real.' Now, this innate enlightenment, within the gate of arising and ceasing, is the essence of deluded dharmas; hence it is called 'the nature of all dharmas.' All deluded dharmas are nothing other than the marks of innate enlightenment, the Buddha's mind; since marks manifest upon their own essence, when the essence illuminates its marks, what difficulty could there be in understanding them that they would not be fully understood? Hence it says: 'their own essence clearly illuminates,' etc. Thus, in the text above, the discernment of the Buddha's saṃbhoga and nirmāṇa functions was located within the minds of sentient beings; here, sentient beings' deluded dharmas are discerned as being upon the Buddha's mind. Truly, because the source of the mind is non-dual, it is so. The Avataṃsakasūtra says: 'As is the mind, so is the Buddha; as is the Buddha, so are sentient beings. The mind, Buddha, and sentient beings—these three are not differentiated.' This is what it means. Using the cognitive power of identical essence, they give rise to superior skillful means to gather and transform sentient beings; hence it says 'possessing great cognitive function' down to 'called the cognition of all modes.'