How Do the Internal and External Dust of Food and Drink Arise, Cease, and Transform?

The act of eating is not necessarily an attachment of the mental faculty. When the Buddha manifested in the human realm, He engaged in eating activities, and the great Bodhisattvas also eat. They harbor no greed or attachment toward food. While some sentient beings eat driven by the attachment of the mental faculty and crave form, sound, scent, taste, touch, and dharmas, others, like the Buddha and Bodhisattvas, are free from attachment and greed. So why do they eat? It is to nourish the physical body, enabling it to maintain normal activities of the five aggregates for the purpose of delivering sentient beings. Ordinary people eat partly to sustain the physical body, but also partly driven by their inherent greed, hatred, and delusion, manifesting these afflictions. In the process of eating, Buddhas and Bodhisattvas are devoid of the afflictions of greed, hatred, and delusion; this is the distinction between Buddhas and ordinary sentient beings.

Food and drink are composed of the four great elements (earth, water, fire, and wind). Even without being chewed, they undergo momentary birth and cessation — the elements arise, instantly cease back into the Tathāgatagarbha, arise again, and return, perpetually changing in this cycle of birth and cessation. Even when food is chewed into fragments, it remains composed of the four great elements. The fragmented food turns into fine particles, ultimately becoming the minutest particles, yet it is eternally a combination of the four great elements, perpetually undergoing momentary birth and cessation.

The food and drink contacted by the sentient being's tongue faculty, oral cavity, and teeth are external dust-objects (form). What the tongue consciousness and body consciousness perceive are internal dust-objects. When the teeth crush the external dust-objects, the internal dust-objects contacted by the body consciousness are also broken down. Ultimately, the external dust-objects turn into fine particles entering the stomach and intestines, and the internal dust-objects contacted by the body consciousness and mental consciousness also enter the stomach and intestines. Finally, the food and drink in the stomach and intestines are completely metabolized and even excreted from the body, causing the internal dust-objects contacted by the body and mental consciousness to vanish. Similarly, the internal flavor dust-objects discriminated by the tongue consciousness and mental consciousness, once they pass from the oral cavity into the esophagus, can no longer be tasted. However, within the stomach and intestines, transformed external flavor dust-objects and internal flavor dust-objects still exist; they are merely beyond the perception of the tongue consciousness. After being metabolized and excreted, both the external and internal flavor dust-objects completely disappear. What is the relationship between these external and internal dust-objects, and how do they transform?