淨名經集解關中疏 2.274

2.274

月上菩薩曰。闇與明為二。無闇無明則無有二。所以者何。如入滅受想定識空無闇無明。一切法相亦復如是。於其中平等者。是為入不二法門　肇曰。二乘入滅盡定六根都滅。雖經晝夜不覺晦明之異。以喻菩薩無心於明闇。

The Bodhisattva Candrottara said, "Darkness and light constitute duality. When there is neither darkness nor light, there is no duality. Why is this? Just as when entering the absorption of the cessation of perception and feeling, consciousness is empty and there is neither darkness nor light, so too are the characteristics of all dharmas. Being equal within this is entering the dharma gate of non-duality."
Sengzhao says, "When followers of the two vehicles enter the cessation absorption, the six sense faculties are entirely quelled. Even if days and nights pass, they do not perceive the difference between dark and light. This is used as an analogy for the bodhisattva having no deliberate mind regarding light and dark."