The Special Function of the Manas in the Absence of Mind Consciousness

When the recollection of the Buddha (buddhānusmṛti) penetrates deep into the manas and transforms the manas's thinking, one can still recollect the Buddha even while sleeping. When Chan investigation arouses questioning doubt in the manas, one continues investigating Chan even while asleep, and one's sleep becomes restless. Because the problem has not been resolved and the manas considers it extremely important, it keeps deliberating (manasikāra) even after falling asleep; the moment one wakes up and opens one's eyes, the mind consciousness suddenly understands—the problem is solved.

Hand over to the manas the dharma that the mind consciousness has not yet comprehended; let the manas hold it in deep questioning doubt and keep deliberating on it, while the mind consciousness does whatever it needs to do. At some unknown moment, the manas resolves the questioning doubt, and the mind consciousness suddenly understands—a sudden great awakening.

Regarding the Buddha-dharma, the manas uses the mind consciousness to study the knowledge and theories of the Buddha-dharma; afterward, the manas digests and absorbs them based on this learned theoretical knowledge, which is like a cow ruminating while at rest. Many people rely solely on the mind consciousness to study everywhere and collect vast amounts of knowledge, then output it again, never understanding how to let the manas absorb and digest it so that it becomes the nourishment they need and turns into their true wisdom. The patriarchs said that when a person without realization expounds the dharma, it is "dharma that enters the ear and exits the mouth," or "dharma explained through sentiment and intellectual understanding." Such a person has not even benefited themselves, let alone others.