The seeing-nature of the tathāgatagarbha is the Buddha-nature

Question: Once, while sitting on the steps recollecting the Buddha, seemingly looking yet not looking, a black object suddenly swept past before my eyes. Startled inside, I wanted to see what it actually 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 that bird flew past within the ever-present conscious mind, just like flying past a mirror that had been reflecting all along. Under normal circumstances, a person has a function that exists whether you look or not—this is the seeing nature, the capacity to see. Is this seeing nature the Buddha-nature?

Answer: A black object suddenly sweeping past before the eyes is the hazy form seen by the eye consciousness. Being startled inside and wanting to see clearly what it was means the manas, not knowing what the thing was, was frightened and wanted to discern it in detail. Before this, the mind consciousness had appeared; the eye consciousness cannot discern on its own—that was the manas' habitual grasping—and the eye consciousness and mind consciousness instantly sensed an object passing before the eyes. If the manas did not habitually grasp, then even if a fierce tiger appeared before the eyes, let alone a black bird, one might not even know it.

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