As Phi has said, connect, unity, movement of inside
The idea of make a connection so that you become one unit with your opponent or an object and then moving your middle as the control of the joined 'unit' is the essence of a great cosmological point. You 'become one' with anything and everything in your environment and you become the central controller of your own universe... that's one way to put it and you begin to see how it is not some spiritualistic or metaphysical point. It is an approach based on a realistic phenomenon; living like this become the Tao.
The unfortunate thing is that the beauty of this reality-based concept usually becomes distorted into quasi-spiritualistic discussions in which nice-sounding words turn endlessly around obvious and often-pretended moralisms uttered by the self-absorbed.
The Tao is supposed to be a journey, not a solipsism.