With ease and great clarity, Chan master Sheng Yen expounds upon huatou practice in Shattering the Great Doubt: The Chan Practice of Huatou. Essentially, the practice involves simply asking, “What is wu?,” over and over again with immense yet quiet focus and with a desire to know.
As with the koan, so with the huatou: the question is not to be answered by conceptual mind. Only direct experience–breaking through delusion–of buddha mind will supply the answer.
Here, I’d like to comment briefly on the meaning of huatou. Sheng Yen:
The Chinese word hua means “words,” sometimes translated as “spoken words,” expressed either mentally or externally. The word tou can mean “head,” “bud,” “wellspring,” or “source.” What is the wellspring of spoken words? Or simply put, what are spoken words? Spoken words are symbols we use to communicate, to think. What lies behind the symbols? What lies behind is the source or wellspring. This wellspring is not some object or some original place from which these symbols come; rather it is precisely emptiness. This emptiness is not something lacking or vacant as in a void. It is actually quite full in that it embodies both sentient beings and buddhas. (24)
Wow, it is hard to even comment on this passage in a way that does what is behind spoken words justice. Not hard–impossible.
When one asks, “What is wu?,” where does the question come from? Where do the words, when they’ve faded away, return to? Not realizing that these questions are not meant to be answered verbally/conceptually, you might blurt out: “The ordinary mind!” But what is ordinary mind? “Brain states!” But what are brain states? “Processes in the brain!” But what is the brain? “Matter!” But what is matter? “The basic stuff of reality!”
No, we are better off admitting that we don’t know, that we don’t have a clue. We don’t really know what is really real. Then the sense of mystery can be felt. Starting here, we let go of conceptual mind and ask again: “What is wu?” The question itself, revealing what has always already been here, brings us back to the source. Taking us everywhere, it takes us nowhere.