三十幅共一轂；當其無，有車之用。埏埴以為器；當其無，有器之用。鑿戶牖以為室；當其無，有室之用。故，有之以為利，無之以為用。
The thirty spokes unite in the one nave; but it is on the empty space (for the axle), that the use of the wheel depends. Clay is fashioned into vessels; but it is on their empty hollowness, that their use depends. The door and windows are cut out (from the walls) to form an apartment; but it is on the empty space (within), that its use depends. Therefore, what has a (positive) existence serves for profitable adaptation, and what has not that for (actual) usefulness.
Legge's Comments
無用, 'The Use of what has no Substantive Existence.' The three illustrations server to set forth the freedom of the Dào from all pre-occupation and purpose, and the use of what seems useless.