What does the tathāgatagarbha rely on to uphold and transform the physical body?

The tathāgatagarbha constantly abides in quiescence and cessation without moving. If He is to manifest any dharma, it must be the result of the manas being stirred—there must always be the manas as an accompanying condition. On the surface, when the tathāgatagarbha forms the nāma-rūpa fertilized egg, transforms and alters the fertilized egg, and repairs the tissues of the material body, it seems that there is no functioning of the manas; in reality, the manas is always involved. The manas forever corresponds to karmic seeds, and the tathāgatagarbha accords with karmic seeds—according with both seeds of merit and seeds of meager merit (alpa-puṇya)—which is the same as according with the manas. The vast majority of the time, when the tathāgatagarbha gives rise to worldly dharmas, it does so on the basis of karmic seeds. Even when the manas is constantly deliberating (manasikāra) and constantly making choices, when the tathāgatagarbha cooperates with the manas, it still must rely on karmic seeds, on the conditions of merit, and on other causal conditions.

If the causal conditions do not permit it, if merit is insufficient, if there are no karmic seeds, or if the karmic seeds have not yet matured, the tathāgatagarbha cannot give rise to dharmas according to the manas's choices. For example, many people wish to be promoted and become wealthy, wishing to possess superior worldly retributions; but without karmic seeds and with conditions not yet mature, they can only continue as before, living the life of ordinary commoners. Take another example: some people have the retribution of chronic illness; no matter how hard they strive, no matter how much money and energy they spend, they cannot restore their bodies to health. Even the merit of an emperor would not suffice; moreover, once an emperor has exhausted his merit, he may commit suicide, be killed, or have his throne usurped. In this world, quite a few people are born with great merit; because from childhood they indulge in and consume this merit to the extreme, by the time they grow up the merit is used up, and they either die early, or live in poverty and hardship, or suffer many calamities and misfortunes.

The retributions of the three realms are drawn along by karmic power, and the tathāgatagarbha turns along with karmic power. But if the power of vows is greater than karmic power, it can draw the tathāgatagarbha to move according to one's aspirations. When ordinary beings make great vows, they will gradually break free from the bondage of karmic power, be reborn transformed and become sages, and ultimately attain buddhahood. Therefore, repentance and making vows is a powerful method of practice. As long as there is a vow—as long as the manas has a vow—sooner or later the day of its realization will come. No vow is an empty vow; all will be realized; it is only a matter of when the conditions become complete. After these great vows are made, the tathāgatagarbha records them, and when the seeds mature, they will come to pass as wished. What we need to do is, first, to make pure great vows and wholesome vows, and second, to strive to bring the seeds of the power of vows to maturity; in the future we will obtain the fruits of those vows.