首楞嚴義疏注經 9.228

9.228

定中研究，心光澄靜。由澄靜故，忽然發見，暗中見物，物是實境，故不隨定出入有無，故云亦不除滅。心細密澄者，觀心微細，密爾澄靜，精光既定，暗境不隱，故夜見物。悟則無咎。

Investigating within concentration, the light of the mind is clear and still. Because it is clear and still, vision suddenly arises: seeing objects in the dark. The objects are real objects, so they do not follow the coming and going, existence or nonexistence, of the concentration; hence it says 'are not eliminated either.' 'The mind finely and densely clarifying': the contemplative mind is subtle and fine, densely clear and still; once the concentrated light is stabilized, dark objects are not concealed, and therefore one sees objects at night. If one is awakened, there is no error.