There is a scene from the Karate Kid movie where Dre is with Mr. Han visiting a Taoist Temple in the Wundang Mountains and a priestess is out on a ledge charming a cobra with her Kung Fu form. This is the most loaded scene from the movie. This short segment contains the full essence of Budo if you can see it. The priestess is not intimidating or challenging the cobra, she is merging with it, energetically and spiritually. It should be obvious that all animals have a dantian, a physical body, an energetic body, and a spiritual body. The priestess is connecting with the snake. She is locking her vibration with its vibration via their dantians. As she becomes one with the snake energetically, she realizes she is one with it spiritually, or ultimately, as well. At this point she is in no danger. Since she and the snake are ultimately one, the snake will not, nor cannot, attack itself. Where the snake moves, she moves; where she moves, the snake moves. As long as she stays connected, vibrates at the same frequency, and has no fear, the snake is not threatened. This requires a firm grasp of non-duality.
This applies to push hands and any combat. If we lock into our partner's energy, follow and stick with no intention of assertion or resistance, and with no fear, the partner cannot perceive another to attack. If our partner attacks and we stay connected, we can disappear and lead him/her to emptiness because it is they who are getting out of synch and we are striking. The same applies to sparring, grappling and two-person application training. If one makes a sudden move and gets out of synch, the partner/opponent should strike. If we have any fear, we will be stiff and unable to unify/blend. This is high level Gongfu and needs to developed and nurtured through practice. The benefits are so much more than we may imagine.
It is through this very physical, practical application of non-duality that we can actualize a higher state of living. Overcoming fear is a first-rate requirement of all spiritual paths. There is no other way to tread them. It is also key in true transformation. While the elementary understanding of martial arts is concerned with self defense and survival of the mean streets of life, at a higher more mature level we transcend labels and definitions. It's all yoga, the art of unification with Self, with energy, with other, with Ultimate Reality