Explanation of Terms in Volume IV of the Śūraṅgama Sūtra

The nature of enlightenment is true emptiness; the nature of emptiness is true enlightenment. The nature of seeing is luminous enlightenment; the luminous essence of enlightenment is true seeing. The nature of consciousness is clear knowing; the luminous enlightenment is true consciousness. The true nature is perfectly interpenetrating.

The nature of enlightenment is true emptiness; the nature of emptiness is true enlightenment. Enlightenment-nature is the true emptiness-nature; the nature of voidness is the true enlightenment-nature. This "enlightenment" refers to the enlightenment of the Tathāgatagarbha. The enlightenment-nature of Tathāgatagarbha gives rise to voidness. Voidness is the boundary of form; where there is absence of form, there is voidness. The essential nature of voidness is the Tathāgatagarbha-nature.

The relationship between voidness, form, and the emptiness-nature mind of Tathāgatagarbha must be clearly understood. Once these two types of emptiness are distinguished, the sutras become comprehensible.

The nature of seeing is luminous enlightenment; the luminous essence of enlightenment is true seeing. Enlightenment-nature is the clear and luminous enlightenment-nature; enlightenment-nature is the clear and luminous seeing-nature. From the clear and luminous enlightenment-nature of Tathāgatagarbha arises the seeing-nature. Seeing brightness, seeing darkness, and seeing voidness are all enlightenment-nature, all being the Tathāgatagarbha-nature.

The nature of consciousness is clear knowing; the luminous enlightenment is true consciousness. The conscious-nature of the six consciousnesses is the clear knowing-nature of Tathāgatagarbha. The luminous enlightenment-nature of Tathāgatagarbha is the true conscious-nature of the six consciousnesses. The conscious-nature arises from the clear and luminous enlightenment-nature of Tathāgatagarbha; thus, it is the Tathāgatagarbha-nature.

The true nature is perfectly interpenetrating. In summary, the natures of the seven great elements—earth, water, fire, wind, space, seeing, and consciousness—are all the nature of true enlightenment Tathāgatagarbha. They interpenetrate perfectly without obstruction, collectively constituting all dharmas of the five aggregates world. This enables all dharmas to manifest according to conditions and mental capacities, their essence being the One True Dharma Realm of Tathāgatagarbha.