大乘起信論裂網疏 2.83

2.83

此即真如門中依言說建立之真實空也。謂阿賴耶中無始無漏種子，全攬真如為體。真如非一切心、非一切心所現境界，亦非覺相，一切皆空。故此無漏種子，亦非一切心、境界相及與覺相。譬如虛空，體非群相。譬如明鏡，本無纖塵也。

This is precisely the genuine emptiness established through verbal explanation within the aspect of tathatā. It means that the beginningless untainted seeds within the ālaya entirely take tathatā as their essence. Tathatā is not any mind, nor is it any object manifested by the mind, nor is it a mark of awakening; all are empty. Therefore, these untainted seeds are also not any mind, marks of objects, or marks of awakening. Just as space in essence is not the multitude of characteristics, and just as a bright mirror originally has not a speck of dust.