Tathāgatagarbha's Seeing of Nature Is Buddha-Nature

Question: Once, while sitting on the steps recollecting the Buddha (buddhānusmṛti), seemingly looking yet not looking, a black object suddenly swept past before my eyes. Startled inwardly, I wanted to see what it was; looking carefully, I saw it was a black bird. At that moment, the eye consciousness saw it first, and the manas sensed whether there might be danger, so without deliberation I was startled. After the startle, I wanted to know what it was, so the mind consciousness arose to discern it carefully, and I knew it was a bird. At that time, it was as if the bird flew past within the ever-present conscious mind, just as something flies past a mirror that is constantly reflecting. Under normal circumstances, a person has a function that exists whether you look or not — this is the seeing nature, the faculty of seeing. Is this seeing nature the Buddha-nature?

Answer: A black object suddenly sweeping past before the eyes — this is the hazy form seen by the eye consciousness. Being startled inwardly and wanting to see clearly what it was — this is the manas, not knowing what the thing was, being frightened and wanting to discern in detail what it actually was. Before this, the mind consciousness had appeared; the eye consciousness cannot discern on its own — that was the manas's habitual grasping. The eye consciousness and mind consciousness instantaneously sensed that an object passed before the eyes. If the manas did not have this habitual grasping, then even if a black bird appeared before the eyes — even if a fierce tiger came out — one might not necessarily know it.

The great-seed of seeing of the tathāgatagarbha gives rise to the seeing nature of the tathāgatagarbha, which is the Buddha-nature. The Buddha-nature is the seeing nature that appears in dependence on the first moon, the tathāgatagarbha — the second moon. The Buddha-nature operates first, and then the seven consciousnesses operate instantaneously. As for the rest, I will not say more; investigate and realize it yourself when your conditions ripen.