Verse 11: The concept of nothing

三十幅共一轂，
Thirty spokes form a wheel hub,
當其無，有車之用。
With nothing (hole in hub), there is a cart to be used.
埏埴以為器，
Mixing clay creates vessels,
當其無，有器之用。
With nothing (inner space), there is a vessel to be used.
鑿戶牖以為室，
Cutting doors and windows make a house,
當其無，有室之用。
With nothing (window and door space), there is a house to be used.
故有之以為利，
Hence, having Something leads to profitability.
無之以為用。
Having Nothing leads to utility.

Comments
This is a philosophy of the principle of invention, a mix of rigidity and flexibility created by a mix of the formed and the formless. The final line can also be interpreted as consuming as much as you need, and that excessive consumption is useless.