大乘起信論義疏 1.56

1.56

問曰：妄法如一柱中，望四微為假，望舍為實，故一柱中總別無障礙。何故但真總別無礙耶？答曰：不例。真法之中以樂成常，還即是常，以成樂義望法之中，不得還以柱令成微，故有障礙。

Question: Regarding deluded phenomena, just as within a single pillar, looking toward the four subtle atoms it is provisional, and looking toward the house it is real, therefore within a single pillar the general and specific are unobstructed. Why is it only in the real that the general and specific are unobstructed? Answer: They are not analogous. Within real phenomena, bliss forms permanence, and that very permanence in turn forms the meaning of bliss; within deluded phenomena, one cannot in turn take the pillar and make it become the subtle atoms, hence there is obstruction.