Tao Te Ching 11 (thing)

Thirty spokes share the wheel's hub;
It is the center hole that makes it useful.
Shape clay into a vessel;
It is the space within that makes it useful.
cut doors and windows for a room;
It is the holes which make it useful.
Therefore benefit comes from what is there;
Usefulness from what is not there.

The use of not

Thirty spokes
meet in the hub.
Where the wheel isn't
is where it's useful.

Hollowed out,
clay makes a pot.
Where the pot's not
is where it's useful.

Cut doors and windows
to make a room.
Where the room isn't,
there's room for you.

So the profit in what is
is in the use of what isn't.

11. Tools

Thirty spokes meet at a nave;
Because of the hole we may use the wheel.
Clay is moulded into a vessel;
Because of the hollow we may use the cup.
Walls are built around a hearth;
Because of the doors we may use the house.
Thus tools come from what exists,
But use from what does not.