The First Month, The Second Month, The Shadow Month

In the Shurangama Sutra, the Bhagavan defines the second moon as the moon formed by pinching the eyes, which is more real than the shadow moon. The wondrous essence of enlightenment spoken of in the Shurangama Sutra refers to the substance of the eighth consciousness, which is the first moon, also known as the original moon. The function arising from the substance of the eighth consciousness is the second moon, which exists dependent upon the substance. For instance, the Buddha-nature of seeing by which the eighth consciousness perceives all dharmas through the six sense faculties is the second moon—it is not the function of the substance of the eighth consciousness. The operation of the mental factors associated with the eighth consciousness, its discerning function regarding all dharmas, is the second moon—it is not the function of the substance of the eighth consciousness. The substance of the eighth consciousness, the first moon, cannot be perceived by anyone, including the Buddha; only the second moon and the shadow moon can be seen.

The shadow moon refers to all illusory phenomena manifested by the eighth consciousness through the second moon utilizing karmic seeds and the seven fundamental elements. This includes material dharmas, mental dharmas, and mental factors.