A Donkey Sees a Well (BS52)

KOAN:

Xaoshan asked the old student De, “The body of reality is like space. It responds to things—manifesting its forms the way the moon appears in the water. How do you explain this responsiveness?”
De said, “It’s like a donkey looking into a well.”
“That’s most of it, but not the whole thing.”
“What’s it like for you?”
“It is like a well looking at a donkey.”

—Book of Serenity Case 52