Among the four modes of birth, the nine abodes, and the twenty-five types of sentient beings, which type of sentient being does a cell belong to?

Cells are the basic structures that make up the living bodies of sentient beings. They are composed of the seeds of the four great elements and have no conscious mind, so they are not independent living beings and are not sentient beings. The composition, arising, ceasing, and transformation of the seeds of the four great elements are the functions of the tathāgatagarbha; therefore, all the functions of cells are the operating mechanisms of the tathāgatagarbha, and all the activities of life are the operating mechanisms of the tathāgatagarbha. This part of the content is especially profound and subtle, extremely difficult to observe—many times more difficult than observing the activities of the manas. All of this belongs to the domain of the wisdom of the seeds of Consciousness-only (yogācāra seed-wisdom), including observing the operating mechanisms of the manas, which also requires this wisdom of the seeds of Consciousness-only. Ordinary people's views of the manas are not derived from direct contemplative practice (vipaśyanā-caryā) of direct perception, so they are all unreliable, and one should not be overly confident.

By observing the various activities of cells under a microscope, one will know how intricate, profound, unfathomable, and miraculous the operating mechanisms of the tathāgatagarbha are. How does He construct living bodies? How does He make living bodies function? How does He make living bodies disappear and perish? From this, one can know that the entire living body is entirely the function of the tathāgatagarbha; therefore, the living body belongs to the tathāgatagarbha, not to the manas-self. The manas has not the slightest reason to claim the living body as its own, yet it goes on endlessly, day after day, with "me, me, me," lacking self-awareness and also lacking awareness of others, knowing nothing at all—and only because of this does it go on endlessly with "me, me, me" and inexhaustible afflictions. This is the most fundamental beginningless ignorance (avidyā).