Thirty spokes radiate from a hub.
When there is nothing in the hub,
the wheel can roll.
Turn clay to make a vessel.
When empty,
the vessel can be used.
Build a room with doors and windows.
When empty,
the room can be used as dwelling.
When there is something, it is beneficial;
When empty, it is useful.
三十辐共一毂(gǔ)，当其无，有车之用。
埏(shān)埴(zhí以为器，当其无，有器之用。
凿户牖(yǒu)以为室，当其无，有室之用。
故有之以为利，无之以为用。
