Thirty spokes converge upon a single hub;
It is on the hole in the center that the use of the cart hinges.We make a vessel from a lump of clay;
It is the empty space within the vessel that makes it useful.We make doors and windows for a room;
But it is these empty spaces that make the room livable.Thus, while the tangible has advantages,
It is the intangible that makes it useful.
I found this passage to be somewhat cryptic, so I will offer only my interpretation.
It seems that the empty space, or the void, is the unknowable source of all existence. While we cannot perceive this ineffable emptiness, it has a direct impact on our physical beings and our daily lives.
I also have the impression that Lao Tzu is cautioning against attachment to material things. Trying to grasp and hoard things in life tends to create mental clutter and creates a barrier between ourselves and the divine essence.
Finally, I can apply this to my meditation practices. I see all the tangible things as the thoughts that clutter the mind. When I meditate, I try (often unsuccessfully) to quiet that mental chatter and open myself to the profound silence which is the subconscious mind. It is impossible for me to describe this connection. As soon as I try to analyze or think about it, the conscious mind takes over and the connection is lost. But those brief moments of deep mental quietude help put the rest of my life and thoughts into perspective.
I would love to hear your thoughts and impressions on this passage. Please feel free to share your thoughts in the comments section. Cheers!
Stuff Jeff Reads 
I see it as a balance between the material or tangible and the unknowable. While the void, or nothingness, powers us we need physical form to accomplish that will.
You can meditate on the chakras but what about the space between the chakras?
There is a link between all physical form and the divine essence.
All are connected by that.
Nice! Thanks for sharing that. Love your idea about space between chakras.
It’s hard to put words to the spaces between the thoughts. The deep moment that is neither this thought nor that. To me, that’s what this passage is about, and seems to be what you’re describing as well.
Yeah, sounds like we share the same interpretation, Amber.
i like the commentary. for me, the wheel always speaks to the concept that life is moving, with the expressions of the elements cyclically interacting with us as individuals and collectives. for us to practice the art of staying centered in the hub allows for optimum perspective, the ego in healthy check, the making and innovating on the physical plane from highest motivation relevant to awareness. (its a tall but edifying order, for sure!)
i think the further examples given are variations on the theme as we all grasp lessons through our experiential lense, connecting with some metaphors better than others.
Wow, great insights! Thank you for adding your thoughts to this post. Cheers — Jeff