It seems to me that the Buddha nature/embryo and the Prajna-paramita/emptiness elements are seen by many... but the dharmakaya/reality body/tathata buddha womb is utterly fundamental in understanding Hui neng.
the old master hides Hui Neng behind the venerated robe and teaches him one thiing and one thing only... suchness. (reality/dharma as it is - none other than the Dharmakaya.)
emptiness... all is empty.
buddha nature... we all have it.
buddha womb... we all see it, live and move and have our being in it.
it has been said that Suchness... "as things are" is the reality of realities, and yet it is totally empty. Things as they are appear to be changing and subject to defilement, but this is only on a subjective level... actually the reality body is always before our eyes. reality is utterly indestructible as one unity/thing. the spirit or womb of the buddha. the reality body which is truth. dharmakaya refers to the truth of reality, which is totally empty and yet utterly real.
The Old Master transmitted to Hui Neng in the Autobiography at the beginning of the Platform Sutra:
One Should be able [anyone] to realize the essence of Mind [Suchness] all the time [its easy]. All things will then be free from restraint (ie emancipated). Once the Tathata (Suchness, another name for the Essence of Mind) is known, [and who doesnt know it?] one will be free from delusion forever, and in all circumstances one's mind will be in a state of "Thusness". Such a state of mind is absolute truth. If you can see things in such a frame of mind you will have known the Essence of mind, which is supreme enlightenment.
"I at once became thoroughly enlightened, and realized that all things in the Universe [all Dharmas] are the Essence of Mind [suchness] itself."
Hui Neng to the Old Master:
"Who would have thought, "I said to the Patriarch, "That the essence of mind
is intrinsically pure!"
[it seems defiled and conditioned, yet fundamentally is immutable, pure and perfect. its what you see, hear and taste every day. the walking to work, the cup of tea, the blaring of the TV, etc.]
please note, that i include [ ] parenthesese where i make a comment of my own. WL. x