The Perception of Tathāgatagarbha Is Buddha-nature

Question: While sitting on the steps reciting the Buddha's name one day, in a state of seeing yet not seeing, suddenly a black object flashed past my eyes. My mind startled, and I wanted to see what it was. Upon closer look, it was a black bird. At that moment, the eye-consciousness saw it first. The manas (mental faculty) sensed potential danger, hence the instinctive startle without conscious thought. After the startle, wanting to know exactly what it was, mind-consciousness arose to carefully discern, recognizing it as a bird. This moment was like the bird flying through the ever-present consciousness, like something passing in front of a mirror that is constantly reflecting. Normally, people possess a function that exists continuously, whether they are looking or not—this is the seeing function, the seeing-nature. Is this seeing-nature the Buddha-nature?

Answer: A black object suddenly flashing past the eyes is the indistinct form seen by the eye-consciousness. The inner startle and the desire to see clearly what it was occur because the manas, not knowing what the object is, becomes frightened and wishes to carefully discern its true nature. Before this, consciousness arose; the eye-consciousness alone cannot discern. This is the habitual grasping of the manas; the eye-consciousness and mind-consciousness instantaneously sensed an object passing before the eyes. If the manas lacked this habitual grasping, one might not notice even if a fierce tiger appeared, let alone a black bird.

The seed of the seeing element within the Tathagatagarbha gives rise to the seeing-nature of the Tathagatagarbha, which is the Buddha-nature. The Buddha-nature is the secondary moon of seeing-nature that manifests based on the primary moon of the Tathagatagarbha. The Buddha-nature operates first, followed by the instantaneous operation of the seven consciousnesses. The rest will not be elaborated here; contemplate and realize it yourself when the causes and conditions ripen.