Studying some texts of Huang-Po, (from Classics of Buddhism and Zen, vol.1, page 290, by Thomas Cleary) when it hits me:
Buddhas, sentient beings, and the one mind are no different, like space without adulteration or corruption, like the orb of the sun illumining the four quarters. When the sun rises, its light pervades the land, but space is never bright. When the sun sets, darkness covers the land, but space is never dark.
States of light and darkness alternate, but the nature of space remains open and empty, unchanging. So it is also with buddhas, sentient beings and mind. If you contemplate buddhas as form of pure illumination and liberation, and you contemplate sentient beings as forms of muddled living and dying in the dark, with this understanding you will never ever attain enlightenment, because you are attached to appearances.
It’s just this one mind; there is nothing else at all to attain. Mind itself is Buddha.
[T]he nature of space remains open and empty, unchanging.
But of course! Hence the use in Zen speak of the image of the mirror and that of the moon, of the surface of lakes and of empty cups to wash, of clear still waters and waves in oceans. They all refer to the exact same thing. It all makes sense now. What else can emptiness be if not the nature of the thing itself? What if not my very nature? That’s all there is to it. Really.
So simple and yet profound indeed.
Do you get it? Can you wrap your Mind around it? I hope you can.