The Relationship Between Dhyana and Anusaya

When in meditative concentration, one requires less sleep as the body does not need excessive rest. This is because meditative concentration itself reduces the activity of the six consciousnesses, thereby diminishing the consumption of the four elements (earth, water, fire, wind). Meditation also causes the manas (mind-root) to grasp at external objects less frequently, reducing physical activity and decreasing the mobilization and control over the entire nervous system. Consequently, the brain's nervous system, internal organs, and the entire body engage in less activity and consume fewer of the four elements. As a result, the body does not become fatigued, and the manas no longer necessitates the decision to sleep.

The deeper the meditative concentration, the less sleep is required, to the extent that sleep may become entirely unnecessary. At this stage, the manas becomes very tranquil, ceasing to engage in deliberate actions and thus no longer excessively activating the brain's nervous system. There is minimal activity of the body consciousness and mental consciousness. The more stabilized the manas, the less it grasps at objects, the fewer regulatory activities occur, the less the four elements are consumed, and the less need there is for sleep or food.

Some individuals, in their daily work, accomplish substantial tasks yet harbor very few mental thoughts. They consume less energy, do not require as much food or as much sleep, and still remain energetic. This indicates that the mental activities of the manas are what most significantly consume the energy of the four elements, while the six consciousnesses themselves do not consume very much. Therefore, even when the workload of the six consciousnesses remains substantial, a reduction in the mental thoughts of the manas decreases overall activity, making work feel less exhausting.

It is evident that the manas is capable of comprehending the state of the physical body at all times and in all places, and can regulate and direct it accordingly. It discerns very acutely, while the consciousness remains unaware of the body's various conditions and still requires the manas to provide hints and alertness.