大乘起信論義記 3.34

3.34

Fourth, regarding the manifesting-matter-unconjoined [defilement]: this is the manifesting consciousness among the five consciousnesses above and the mark of objective realms among the three subtle [marks] above. Just like a bright mirror manifesting material images, it relies on fundamental avidyā stirring [the mind] so as to cause it to manifest objective realms. Because on the eighth ground one attains mastery over the three kinds of worlds and the nature of matter accords with the mind without obstruction, it is said that 'it can be separated from by relying on the ground of mastery over matter'. Because in stages without mastery over matter the manifesting consciousness does not perish, in this stage that mark is dispelled.