Boundless wind and moon—the eye within eyes,
Inexhaustible heaven and earth—the light beyond light.
The willow dark, the flower bright—ten thousand houses;
Knock on any door—someone will answer.
– Preface to the Blue Cliff Record
So, whatever your condition is, you can see the “I have joy.” Out of that emptiness, out of what seems unpromising—the dark material, the valley spirit, the enigma, out of the mystery, out of what I don’t understand—it just appears. The joy just appears.
The Heart Sutra in the context of its relationship to koans and what koans are. I want to pursue that line a little bit. And the first thing to say about – probably the first attitude people have to koans is that they are a sort of tool, a gadget of some kind, and you use them and you concentrate on them, and you use them – a can opener for the mind