Recently, I came across a "Zen story" which probably hoped to be an explained koan:
A Zen student said to his teacher "Master, I have an ungovernable temper. Help me get rid of it."
— "You have something very strange," said the teacher. "Show it to me."
— "Right now I cannot show it to you."
— "Why not?"
— "It arises suddenly."
— "Then it cannot be your own true nature," said the teacher, "if it were, you would be able to show it to me at any time. Why are you allowing something that is not yours to trouble your life?"
Thereafter whenever the student felt his temper rising he remembered his teacher’s words and checked his anger. In time, he developed a calm and peaceful temperament.
This definitely appears to me as a modification of a dialogue between Huike and his teacher Bodhidharma… and a classical koan:
Huike said "Your disciple's mind has no peace yet. I beg you, Master, please put it to rest."
Bodhidharma said "Bring me your mind, and I will put it to rest."
Huike said "I have searched for my mind, but I cannot find it."
Bodhidharma said "I have completely put it to rest for you."
Traditionally, koans don't come with explanations: their whole purpose is to create doubt in the midst of certainties (including 'Buddhist' certainties and dogma)! They raise questions —usually in the form of 'contradictions' (for the ignorant mind still trapped in ignorance and notably in dualism). And Korean have a saying: « Great doubt, great awakening. Small doubt, small awakening. No doubt, … »
Revising koans to make them understandable (immediately upon reading them) misses the point!
Moreover, even though there exist 'classical' answers, koans do not come with only one answer. So any explication reduces the vast possibilities, pretending there's only one non-subjective answer, forgetting that the student has to embody the answer in their individual, subjective circumstances, forgetting that wisdom requires navigating between the two truths, not merely sticking to non-dualism!
When someone recently asked for confirmation that « There is only one answer to that old koan, isn't it... », I could only reply: « Certainly not, a koan with only one answer is not a koan: it's just dogma! »
Amazingly, this was the 無/mu koan (which inspired my domain name http://koan.mu). This koan explicitly exists in two versions to ensure students don't cling to an extreme!
The first version rejected directly the claim that there's only one answer:
A monk asked "Does a dog have a Buddha-nature or not?"
The master said "Not [Mu]!"
The monk said "Above to all the Buddhas, below to the crawling bugs, all have Buddha-nature. Why is it that the dog has not?" [dogmatic certainty, delusion that there's only one answer…]
The master said "Because he has the nature of karmic delusions".
A koan is a tool to help you enquire into the nature of reality, it doesn't presume the answer. If you think there's only one answer, you're grasping at the koan the wrong way. It's an open question, not a rhetorical question (with some implied / implicit answer), it's a true question: answer unknown? Look! Look!
The second version of the 無 koan is to ensure you don't take the previous answer (no!) —from the same Zen master— out of context:
A monk asked Master Joshu "Does a dog have Buddha Nature?"
Joshu replied "Yes." [Wait! What? Why?]
And then the monk said "Since it has, how did it get into that bag of skin?"
Joshu said "Because knowingly, he purposefully offends."
At the end of the day, explanations will usually damage the richness of a "public case".
For example, in the original koan between Bodhidharma and Huike, the point is not about "anger" (not to be reified) but about "mind" (not to be reified): if you cannot find the mind, don't identify with it!
The initial koan might be more cryptic than the revised version, but it is also wider, for it doesn't need to taint the mind with a particular emotion: the mind is not to be found, not to be pinned down, whatever its object!
In Japanese Buddhism, they indeed went on to label this trait of 'mind', as 無心 / mu-shin (in English: no-mind)… which ended up in a Hollywood movie!