The background story of this Koan
The wheel is one of the most important inventions in human history. In China it was believed a legendary craftsman of ancient times, called Keichu, invented the wheel and made the first cart.
The Koan refers to a much later time, when lighter wheels with spokes could be made.
In a modern understanding the Koan sounds like cultural pessimism: if we take all our features away from everyday life, what would change?
Nothing would change, Zen says and gives no explanation beside: toot, toot.
What next?
Traditional Commentaries and .... Poems (Gata)
Mumon's comment: If anyone can answer this question instantly, his eyes will be like a comet and his mind like a flash of lightning.
Wumen says: If even directly below you are able to be clear, then your eye is like a shooting star and your function as if snatching away lightening.
What next?
The Gata
When the hubless wheel turns,
Master or no master can stop it.
It turns above heaven and below earth,
South, north, east, and west.
The function of the wheel is to turn in place.
Those who attain are still confused.
Four dimensions, above, below,
South, north, east, and west.
What next?