The knowing nature and hearing nature of each consciousness

Question: When recollecting the Buddha in daily practice, besides knowing the Buddha's name, there is also a knowing that knows the recollection of the Buddha—what is that knowing?

When contemplating what the Buddha taught about "sound" and "hearing," one can clearly experience what the "hearing" that hears is, yet there is still a "knowing" that knows "hearing." What is this "knowing"?

Answer: Knowing the Buddha's name and the sound of reciting it is the knowing of the mind consciousness, and also the knowing of the ear consciousness. Recollecting the Buddha is the mind consciousness recollecting the Buddha, and the knowing that knows one is recollecting the Buddha is still the knowing of the mind consciousness; it is the mind consciousness's introspection, the functional operation of the mind consciousness's self-validating cognition (sva-saṃvitti-saṃvitti-bhāga).

The hearing that hears sounds is primarily the hearing nature of the mind consciousness, assisted by the hearing nature of the ear consciousness. The knowing that knows the hearing of sounds is the knowing of the mind consciousness; it is the mind consciousness's introspective function, the functional operation of the mind consciousness's self-validating cognition (sva-saṃvitti-saṃvitti-bhāga).

Of course, when hearing sounds, there are four consciousnesses: not only the mind consciousness and the ear consciousness, but also the seventh consciousness and the eighth consciousness. As for all hearing natures, the eighth consciousness is primary, yet on the surface it is all the hearing of the mind consciousness and the ear consciousness. The hearing nature of the eighth consciousness is extremely hidden and difficult to know, and the hearing nature of the manas, the seventh consciousness, is likewise hidden and difficult to know. Ordinary people cannot observe these two kinds of hearing nature; the hearing nature of the mind consciousness is comparatively easier to observe.