Before attaining realization, everything is speculation and imagination

Question: Is it wrong to say that the physical body is the tathāgatagarbha? Can one only say that the physical body is the tathāgatagarbha-nature?

Answer: The physical body and the tathāgatagarbha are related as bread is to flour. If I say that all dharmas are the tathāgatagarbha, that is correct; but if someone else says so, it would be wrong. Because I can genuinely contemplate and practice (vipaśyanā-caryā) this in accordance with reality, whatever I say makes sense; for those who have not achieved such contemplative practice, nothing they say is right. If you have realized that principle, you can speak of it horizontally or vertically—however you put it, nothing is inverted. Without realization, it is merely conjecture and imagination.

On all dharmas there is the functioning of the Buddha-nature; all are the result of the Buddha-nature's functioning. Therefore, in the Śūraṅgama Sūtra the Buddha said: all dharmas are the tathāgatagarbha-nature.

Only after the Buddha-nature functions can the tathāgatagarbha create and fabricate. The Buddha-nature is analogous to the eyes, while the mental factors (caittas) are analogous to the hands and feet.