Why Is Mental Clarity Greater at Night Than During the Day?

Question: When meditating at night and contemplating the Dharma principles, even after rising from meditation, I only seemed to understand vaguely. With unresolved questions lingering in my mind, I fell asleep. In the middle of the night, I suddenly gained clarity. At the moment of realization, my mind felt exceptionally clear and lucid, and I became too excited to fall back asleep. Who was it that understood in the middle of the night?

Answer: If the issue contemplated is quite profound and remains suspended in the mind, it means the manas (mind root) is also involved in the deliberation. If no conclusion is reached and the contemplation remains unresolved, the consciousness may become fatigued, shift its attention, or cease altogether. However, the manas will continue its deliberation, and at some unknown point, it may resolve the matter clearly.

Many issues become clearer when contemplated at night rather than during the day. Why is this? Because there are fewer distractions, the manas is relatively more focused and participates more actively in the deliberation. Is it the consciousness or the manas that engages in grasping (clinging to objects)? It is the manas that grasps, but without the cooperation of the six consciousnesses, the grasping of the manas diminishes. Therefore, when the six consciousnesses quiet down, the manas can concentrate its energy to deliberate on a single issue alone. At night, with the absence of the six consciousnesses, the grasping of the manas lessens. Without the six consciousnesses disturbing it with differentiated information, the manas begins to ruminate, focusing intently on the Dharma principles that the consciousness failed to comprehend. Thus, it is possible to suddenly understand the Dharma principles in the middle of the night.