Commentary on the Pitāputrasamāgama Sūtra (LVII)

What is the eye base?

Original text: O great king, what is the eye base? It is the pure form produced by the four great elements—the earth element, water element, fire element, and wind element. If the earth element is pure, then the eye base is pure. If the water, fire, and wind elements are pure, then the eye base is pure.

Explanation: The Buddha said: Great king, what is the eye base? The eye base is the pure form faculty constructed by the four great elements: earth, water, fire, and wind. If the earth element is pure, then the eye base it constructs is pure. If the water, fire, and wind elements are pure, the eye base formed through their harmonious combination is pure.

The eye faculty is a material phenomenon composed of the four great elements—earth, water, fire, and wind—united together, containing the solidity of earth, the moisture of water, the warmth of fire, and the mobility of wind. The eye faculty includes the gross eye faculty on the face and the subtle eye faculty at the back of the head, both formed by the four great elements.

The four great elements are innate seeds within the Tathāgatagarbha. When the causes and conditions for the birth of the eye faculty mature, the Tathāgatagarbha projects these seeds, thereby forming the eye faculty. Both the internal and external eye faculties gradually develop within the mother’s womb. In the Śūraṅgama Sūtra, the World-Honored One describes the human eye faculty as resembling a grape cluster—this is the eye base.

The seeds of the four great elements—earth, water, fire, and wind—within the Tathāgatagarbha are originally pure, free from defilement and afflictions such as greed, hatred, and delusion. These four elements combine in specific proportions to form the eye faculty. Variations in the proportions result in different material phenomena. Because the four great elements are pure, the eye base formed is pure, devoid of afflictions or defilements. However, the six consciousnesses—eye, ear, nose, tongue, body, and mind—that arise dependent on the eye base as a condition are defiled and afflicted. The eye base itself is undefiled and devoid of emotions like joy or sorrow, as it lacks mental activity.