大乘起信論廣釋卷第三．四．五 3.51

3.51

[Treatise:] In this way, undefiled [and defiled dharmas … down to …] differences of illusion.
[Commentary:] This is the application to dharma. 'Conforming to the differences of defiled illusions' refers to the dharmas of avidyā. Because that avidyā runs contrary to samatā, its nature naturally has differences. It speaks of the intrinsic differences of fundamental avidyā, because afflictions such as self-view and love-attachment arise with differences based on avidyā. The various undefiled dharmas conform to samatā; discussing their nature directly, there are no differences, but solely in accordance with the differentiated characteristics of defiled dharmas, the inherent virtuous qualities of original awakening are spoken of as differentiated. Furthermore, through counteracting those defiled differences, the myriad virtuous qualities of initial awakening are accomplished as differentiated. Although these two dharmas manifest karmic functions, both are tathatā manifesting in accordance with conditions: appearing so yet lacking substance, they are generally named 'karmic illusions'.