Lecture Notes on the Sūtra of the Collection of the Father and Son (10)

What is the internal earth element?

Original text: 大王。云何为内地界。谓于内身。所生硬涩。发毛爪齿。皮肉筋骨。若内地界不生。亦无有灭。则无集行。

Explanation: The Buddha said: Great King, what is the internal earth element? The earth element is the earth-element seed within the tathāgatagarbha. Because the tathāgatagarbha possesses the earth-element seed, it can manifest the hardness of material form (rūpa), and can transform and produce the living environment of the material world and the bodily faculties of sentient beings. The internal earth element is the earth-element component within the physical body of sentient beings—the parts of the physical body that possess hardness, such as the hair, nails, teeth, skin, muscles, sinews, bones, and other tissues that have the hard earth nature.

The internal earth element begins to arise when one enters and settles in the mother's womb. When the manas enters rebirth into the fertilized egg, the tathāgatagarbha outputs the earth-element seeds to transform and generate the physical body of the fetus; otherwise, the physical body would have no earth-element component, and the body would be limp like water, unable to walk, stand, sit, or lie down. Since the earth element has arising, it must have ceasing; with arising and ceasing, the five-aggregate body can be accumulated, and there is bodily action. If the earth-element seeds do not arise within the physical body, then there can be no ceasing either, and the five-aggregate body cannot be accumulated. A dharma with arising and ceasing is a false dharma, not a true dharma; it is a delusive dharma, an empty dharma; therefore we must not crave, cling to, or grasp it.