大乘起信論裂網疏 3.70

3.70

'Mind-nature' refers broadly to the nature of the mind-kings of the eight consciousnesses and the various mental factors; that is, the immutable nature of tathatā. 'Ignorance' refers precisely to the subtle delusion regarding phenomena associated with the seventh consciousness, not truly knowing that the true Dharma is one. 'The marks of a defiled mind appear' refers broadly to the mind-kings of the eight consciousnesses and the various mental factors, all having the four aspects arising in other-dependent fashion. 'Constantly luminous and clean, without alteration': since the four aspects of each mind-king and mental factor all fully grasp tathatā as their essence, and tathatā accords with conditions yet is immutable, they are constantly luminous and clean, like gold being made into various vessels, where all vessels remain gold. 'Furthermore, because its original nature is free from discrimination', etc., specifically refers to the objective aspects transformed by the mind-kings and mental factors, which also take the mind-nature as their essence; the entire essence of the mind-nature has never undergone any change, and there are decidedly no sense-realms outside the mind.