大乘起信論義記 2.129

2.129

舉失中言是故者，是前無念名為覺故，即顯有念不得名覺。以從本來等者，顯不覺所以，即金剛已還一切眾生未離無始無明之念，故不得覺名。然則前對四相夢之差別故說漸覺，今約無明眠之無異故說不覺。如《仁王經》言「始從伏忍至頂三昧照第一義諦，不名為見。所謂見者，是薩婆若故。」此之謂也。故說無始無明者，結成不覺義也。此顯無有染法始於無明，故云無始也。又無明依真，同無元始故也。

In presenting the fault, 'for this reason' means: because the aforementioned thoughtlessness is called enlightenment, this reveals that having thoughts cannot be called enlightenment. 'Because from the beginning' and so forth reveals the reason for non-enlightenment: that is, from before the vajra[-like samādhi] backward, all sentient beings have not been free from the thoughts of beginningless avidyā, and therefore do not obtain the name of enlightenment. Thus, previously, in contrast to the differences among the dreams of the four marks, gradual enlightenment was spoken of; now, in terms of the non-difference of the sleep of avidyā, non-enlightenment is spoken of. As the Renwang jing says: 'From the forbearance of subduing up to the summit samādhi, illumining the ultimate truth is not called seeing. What is called seeing is sarvajñatā.' This is what it means. 'Therefore it is called beginningless avidyā' concludes and establishes the meaning of non-enlightenment. This reveals that there is no defiled dharma that begins prior to avidyā; hence it says 'beginningless.' Furthermore, avidyā relies on the real, and likewise has no primary origin.