起信論疏筆削記 12.27

12.27

此約下，二、結揀。意明無前之忽然，非有始之忽然也。言無前者，以此無明最微細故。更無有法前於此者，前即始也。由無始起之本故，故說忽然。故本疏云：以起無初。故肇公云：「如鏡忽塵，如空忽雲。」即斯義也。

"This is in terms of..." Below, second: concluding and discerning. The intention is to clarify that it means "sudden" in having nothing prior to it, not "sudden" in having a beginning. Saying "having nothing prior" means that because this avidyā is the most subtle, there is no dharma prior to it; "prior" means "beginning." Because it has no basis of beginning, it is said to be "sudden." Therefore the base commentary says: "because its arising has no beginning." Hence Master Zhao said: "Like a mirror suddenly gathers dust, or the sky suddenly gathers clouds." This is precisely the meaning.