The traditional shakuhachi creation myth begins in 9th-century China, with a fellow named Pǔhuà 普化, pronounced "Fuke" in Japanese. Pǔhuà didn't even play the flute, and for centuries after his death was known primarily for his bizarre guest appearances in the records of Línjì "Shouting and Hitting" Yìxuán (a.k.i.J.a. Rinzai). Nevertheless, the wandering shakuhachi-playing monks and rascals of medieval Japan deemed him the founder of the Fuke sect to which they claimed allegiance, and this has remained the official story ever since, notably recorded in the Fuke sect's Edo-period Kyotaku denki 虚鐸傳記 ("Transmitted record of the empty bell").

Pǔhuà, the KD informs us, had a habit of roaming the streets ringing a bell and saying cryptic things (this part was borrowed from the Records of Rinzai). This so impressed a certain would-be but rejected disciple named Zhāng Bó 張伯 (a.k.i.J.a. Chō Haku) that Zhāng went ahead and made the first shakuhachi. He then used it to imitate the sound of Pǔhuà's bell. Thus the hollow flute is the "empty bell", and you have compositions named things like "Empty bell" (虚鈴, "Kyorei") and "Yearning for the bell" (鈴慕, "Reibo").

I'm not going to get into the actual historicity of all this, because Max DEEG already wrote an excellent paper [PDF] on the topic (f'rex: "It is important to keep in mind that the term Fuke-shū does not actually occur before the Denki [...] In my opinion, this clearly shows that it was the tradition of the Denki which first capitalised on the name of Fuke"). But as you might expect I have read the Kyotaku denki (specifically, 虚鐸傳記國字解, the 1781 edition containing commentary and explanation in regular Japanese) and today I thought I would talk about the most arcane part of the text: the words Pǔhuà cried in the streets as he rang his bell.

The original Chinese given in the Kyotaku denki, directly copied from the Records of Rinzai, is:

明頭来、明頭打、暗頭来、暗頭打。四方八面来、旋風打。虚空来、連架打。

Deeg provides this translation for the version in the KD (after the Koji ruien 古事類苑):

If there comes a bright head I beat the bright head; if there comes a dark head I beat the dark head; if all the four directions and all the eight sides come I beat like a whirlwind; if the void comes I beat with the pestle.

... And this translation for the original in the Rinzai (after Iriya 1989):

"If my common essence [lit.: a bright head] comes I hit my common essence; if there comes my hidden essence [lit.: a dark head] I beat the hidden essence; if all the four directions and all eight sides come I beat like a whirlwind; if heaven (or: void) comes I beat like a pestle."

Christopher BLASDEL has translated Pǔhuà's words thus:

If attacked from the light, I will strike back to the light. If attacked from the dark, I will strike back in the dark. If attacked from all four quarters, I will strike back as the whirlwind. If attacked from emptiness, I will lash out like a flail.

And in 1977, TSUGE Gen'ichi's published an English translation of the Kyotaku denki that had Pǔhuà saying this:

Myōtōrai myōtōda, antōrai antōda. Shihō hachimenrai (ya), senpūda. Kokūrai (ya), rengada. "If attacked in the light, I will strike back in the light. If attacked in the dark, I will strike in the dark. If attacked from all quarters, I will strike as a whirlwind does. If attacked from the empty sky, I will thrash with a flail."

Tsuge is not just being pendantic in including the Sino-Japanese pronunciation here. The Kokuji kai part of the KD — that is, the part that explains what it means in Japanese — does the exact same thing. 振鐸遊干市對人毎曰 is glossed in furigana as Taku o furutte, ichi ni asonde hito ni mukatte wa tsune ni iwaku ("roam the streets shaking his bell, saying to everyone he met..."), but the magic phrase is furiganified only as Myōtōrai myōtōda.... Tsuge, therefore, is simply maintaining an extra layer of foreignness that was there in the original.

However, the Kokuji kai includes explanations as well as glosses. Here's what it has to say about Pǔhuà's routine:

是普化（ふけ）ぜんじの語（ことば）にて。即（すなはち）虚無僧（きよむそう）の本則（ほんそく）とする第一義（だいいちぎ）なり。是をとけば第二義にたつ。しかれどもしばらく和して其故をしらしむ。まづ明頭来明とう打（だ）とは。あからさまに来（き）たらばあからさまに打てやらふ。くらまぎれに来（き）たらばくらまぎれに打てやらふなり。頭（とう）の字（じ）を付（つけ）たるは出（で）やひがしらに打（うつ）といふ義也。漢（かん）来（きた）れば漢（かん）現（げん）じ胡（こ）来（きた）れば胡（こ）現（げん）じるの心なり。あきらかなる場（ば）ならばあきらかに。くらきところならばくらまぎれ。我（わが）法（ほう）は明暗（みやうあん）にかゝはらぬそ男女貴賎（きせん）賢愚（けんぐ）にも心のあきらかな。心のくらきにもかゝはらぬといふを。暗（あん）とうらいやあんとうだとはいふなり。四方八めんらいやせんふうだとは四方八面よりくるときは。つじ風のまふがごとくにうつとなり。是市町（いちまち）に出られたる故。つじかぜとよびかけての説法（せつほう）なり。こくうらいやれんがだとは。こくうよりくるときはからさほにて。むぎをうつやうに。うつとなり。このうつといふ。つゑはことのほかに。ありがたき杖なり。此語（ご）が即（すなはち）人をさとす杖にて。萬人のねふりを覚（さま）すよびこゑなり。一切衆生（いつさいしゆじやう）皆（みな）明暗（みやうあん）のうちに生死（しやうじ）出入（しゆにう）するをあはれみ。老婆（らうば）心切（しんせつ）の托鉢（たくはつ）によせて万物（まんもつ）をして成佛（じやうふつ）なさしむと也。宗門（しうもん）の道（みち）にいりて。禅法（せんぼう）をまなび。明師（めいし）にあふてくはしく知るべし

In English:

These are the words of Pǔhuà [Fuke] and therefore the supreme truth which the komusō make their central principle. Reasoning about these words leads only to secondary truths.

Here the author is very careful to insist that the "central principle" (本則) of the Fuke sect is (a) ineffable and (b) authentically and inalterably a part of the established Zen tradition on the mainland — because, remember, these words of Pǔhuà's come from another document which was already 100% respectable.

Nevertheless I shall translate and explicate them to some extent. First, "Myōtōrai myōtōda" means "Come openly and I shall strike openly. Come by darkness and I shall strike in the darkness." The character "tō" [頭] means that the strike will be immediate upon meeting. It is the same meaning as "When a native comes, a native appears [in the mirror]; when a foreigner comes, a foreigner appears."

This is a quote from the Blue Cliff Record, or maybe more directly Dōgen's Shōbōgenzō.

"In a well-lit place, in the light; in a dark place, by darkness; our Law does not distinguish between light and darkness, nor between man and woman, wealth and poverty, wisdom and foolishness, the light-souled and the dark-souled": this is what is meant by "Antōrai ya antōda."

Note that some extra syllables are starting to creep into the mantra; this is probably where Tsuge got them.

"Shihō hachimenrai ya, senpūda" means "Come from all around me, from every direction, and I shall strike like a whirlwind." Here he calls his sermon a whirlwind because he is out in the streets of the market.

I'm not quite sure what the intended connection here is. I think it might be that the word used for "whirlwind" in Japanese here, tsujikaze, includes (and is etymologically related to) the word tsuji, meaning "crossroads."

"Kokūrai ya, rengada" means "Come from nothingness and I will strike like one threshing wheat with a flail." The staff which so strikes is a welcome staff indeed. These words are a staff that enlightens people, a call that awakens the sleeping multitude. Taking pity on all sentient beings, who are between darkness and light as they pass between birth and death, he became a mendicant out of kindness to help all beings attain Buddhahood. Enter a school of the Law, learn the way of Zen and meet with an enlightened teacher to learn the details.

I'm not done yet. Checking my two different Iwanami editions of the Rinzai roku, I find agreement that the 明 ("light" or "bright") here implies distinction or differentiation, whereas 暗 ("dark") implies the opposite — unity, equality. (Naturally, these are two sides of the same coin: "平等即差別、差別即平等".) They also tend to prefer translations like 受ける (receive), 応じる (reply) and 始末する (dispose of) to plain old 打つ (strike, beat). IRIYA Yoshitaka 入谷義高 further claims that Pǔhuà's words are mostly in three-character phrases because he was actually singing them to a three-character rhythm characteristic of popular songs at the time.

In closing, I humbly offer a new Pǔhuà translation for the ages, distilled from a loving mash of all of the information above.

There once was a Buddhist named Pǔhuà
Who said "Light or dark, I'm where you are!
"Come from all sides? I'll whirl!
"Come from nowhere? I'll flail!"
That obliging old Buddhist named Pǔhuà!