The body is the bodhi tree
The mind is like a bright mirror's stand.
At all times we must strive to polish it
and must not let dust collect.
Huineng wrote this:
Bodhi originally has no tree.
The bright mirror also has no stand.
Fundamentally there is not a single thing.
Where could dust arise?
Hongren praised the first verse publicly, but secretly choose Huineng's verse, and made became the Sixth Patriarch. Shenxiu became a teacher of the "Northern School" of Zen, and over time, the different emphases of the two verses lead to the split of Chan into "gradualist" (jian jiao漸教) and "sudden" (dun jiao 頓教) schools.
So, was Huineng "right" and Shenxius's “wrong”? My own heart teacher, Thich Nhat Hanh, has commentary on this particular Sutra, and he decries the split, saying both verses point to truth. In my practice, I have found this integral approach of Thich Nhat Hanh to be truly non-dual in a way that neither verse by itself can be.
In terms of liberation, what finally matters is openness to whatever unbinds--which might mean cleaning self-evident dust, or seeing that there’s no dust to clean. Cleaning the mirror of consciousness of obvious dirt and stains, we begin to apprehend the mirror’s original “non-dusty” nature. Likewise, glimpsing the “non-dusty” nature of bodhi, of original mind, we immediately see and spontaneously remove whatever would obscure this clarity.
Not being stuck in any view, we are better able to see the truth of the matter, and thus discern what might be needed in any situation. We can then respond to any situation with greater wisdom, compassion, and clarity of mind.
Intellectual debates in Zen about whether there is anything to "do," or "not do," are, to me, just the concept-hindered mind looking at the dharma in terms of “sticky” views. We risk missing the beautiful moon of enlightenment while arguing about the nature of the finger that’s trying to point at it!
Maybe the true Zen answer to both poems is simply, "Is that so?" And then, go see!