What is the capacity of the mind?

A great mind capacity accomplishes great things; a small mind capacity accomplishes small things; with no mind capacity, nothing can be accomplished. What does mind capacity refer to? Mind capacity refers to the measure of dharma that the mind can contain. What does "the mind embraces the great void, and its measure pervades worlds as numerous as sands" mean? It means that what the mind contains is so vast that it embraces the great void itself, and the mind's measure extends throughout worlds as numerous as dust and sand. Besides the Buddha-mind with its eight consciousnesses being able to embrace the great void and pervade sand-like worlds, the tathāgatagarbha of sentient beings is also like this.

Although the tathāgatagarbha embraces the great void and pervades sand-like worlds, the tathāgatagarbha is the tathāgatagarbha—it does not mean that the seven consciousnesses are also like this. For many people, their tathāgatagarbha can embrace the great void, yet their own seven consciousnesses can only contain themselves, plus their own family members and relatives. With such a small mind capacity, nothing can be accomplished. It is very difficult for sentient beings' mind capacity to be like that of Buddhas and Bodhisattvas, containing the entire Buddhist enterprise and the sentient beings of the whole dharmadhātu. Without this mind capacity, if one diligently strives day after day solely for one's own personal gain, considering only one's own affairs and those of family and relatives, then seeking the Buddha-way with such a mind and hoping to gain benefit in the Buddha-dharma is impossible.

Some people, at the slightest disturbance, scurry away with their heads in their hands and hide; no matter what happens in Buddhism, they resolutely refuse to step forward, yet when they themselves have some matter, they seek help everywhere. If people with such mental conduct undergo the suffering of birth and death through long kalpas, it is not unjust. Many people rely on Buddhism, taking Buddhism as their home, hoping to receive the blessings of the Three Jewels from Buddhism; yet when the Buddhist family has matters and the Three Jewels need protection, these people all hide far away, watching the spectacle of Buddhism and the Three Jewels from the sidelines. How can such people be Buddha's disciples? How could they possibly receive the blessings of the Buddhist Three Jewels? There are also some people who are immersed in worldly trivialities, with afflictions that never cease; their vision is as narrow as that of ants; every day it is nothing but disputes and conflicts, entangled endlessly, distressed and afflicted, never awakening.

The Śūraṅgama Sūtra says: 不知色身，外洎山河虚空大地，咸是妙明真心中物。The five-aggregate body extends from within to without, and its scope is vast indeed—it is not merely the size of one's own physical body. So do not cling day after day to trivial matters; how much better it is to grasp the great matter of birth and death! Every day it is all illusory, ethereal things—the vision is too narrow. If one broadens one's vision and opens up one's mind capacity, all dharmas will become empty; how wonderful it would be for the mind to be empty, quiescent, ceased, liberated, and at ease—why must one day after day endlessly engage in greed, hatred, delusion, and afflictive actions? Why can't the mind capacity be opened? That is because of heavy karma, meager merit (alpa-puṇya), lack of wisdom, and short-sighted knowledge, which result in the mind's small capacity. The principle of cultivation clearly seems to be just so, yet one simply cannot accomplish it—just like clearly seeing high mountains and great seas through a telescope, yet being unable to personally arrive at that scene. Being stuck at the level of theory, unable to accomplish anything in actual practice, is precisely because the mind capacity cannot be opened.