Thirty spokes join at the hub:
their use for the cart
is where they are not.
When the potter’s wheel makes a pot,
the use of the pot
is precisely where there is nothing.
When you open doors and windows for a room,
it is where there is nothing
that they are useful to the room.
Therefore being is for benefit,
Nonbeing is for usefulness.

– Thomas Cleary

Thirty spokes converge on a hub
but it’s the emptiness
that makes a wheel work
pots are fashioned from clay
but it’s the hollow
that makes a pot work
windows and doors are carved for a house
but it’s the spaces
that make a house work
existence makes a thing useful
but nonexistence makes it work

– Red Pine

Thirty spokes join the wheel nave
And make of void and form a pair,
And a wagon’s put to use.
Clay is thrown to shape a vase
And make of void and form a pair,
And a vessel’s put to use.
Door and window vent a room
And make of void and form a pair,
And a room is put to use.
Thus the value of what is
Depends for use on what is not.

– Moss Roberts