大乘起信論裂網疏 4.110

4.110

只此現前介爾之心，性即真如，眾生於真如中妄見生滅，猶如迷人謂東為西，則真如之外無生滅也。迷人雖復謂東為西，而東仍自東，則迷人之所謂西原即悟人之東，可譬生滅之外無真如也。謂心為動，合前謂東為西，是即真如而成生滅。心實不動，合前東仍自東，是離生滅更無真如。故苟能知動心，即不生滅，譬如能知所謂之西原即是東，即入真如門也。一心而分迷悟兩門，兩門究竟只此一心，但貴以知翻彼迷謂而已。迷者，即無明也。謂者，即妄想也。知者，即始覺也。本應如是了知，更無別知，故云始覺即本覺也。初顯示實義竟。

This very momentary mind right before us has tathatā as its nature. Sentient beings falsely see arising and ceasing within tathatā, just as a lost person takes east to be west; thus, outside of tathatā there is no arising and ceasing. Although the lost person takes east to be west, east still remains east; thus, what the lost person calls west was originally the east of the person who understands, which can be an analogy for there being no tathatā outside of arising and ceasing. Taking the mind to be moving matches the earlier taking east to be west; this is tathatā becoming arising and ceasing. The mind being actually unmoving matches the earlier east still remaining east; this is there being no tathatā apart from arising and ceasing. Therefore, if one can know that the moving mind is itself neither arising nor ceasing—analogous to being able to know that what was called west is originally east—one immediately enters the aspect of tathatā. The one mind is divided into the two aspects of delusion and awakening, but the two aspects are ultimately only this one mind; the only essential thing is to overturn that deluded perception with knowing. Delusion is avidya. Taking [something to be so] is deluded thinking. Knowing is initial awakening. It should fundamentally be understood in this way, with no other separate knowing; therefore it is said that initial awakening is original awakening. The first part, showing the real meaning, is concluded.