大乘起信論裂網疏 2.83

2.83

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.