Many years after my teacher showed me the empty sleeve, I came across Wang Yongquan’s explanation of 开合相寓 (kāi-hé xiāng yù) — opening and closing mutually containing one another. His words gave language to an experience my teacher had demonstrated years before.

Only then did I begin to understand what my teacher had been trying to show me.

I was practicing Brush Knee and Twist Step. My teacher watched quietly. He stepped forward to correct my movement. He didn’t speak English. My Chinese was next to none.

He watched. Then lightly slapped my lead hand. I thought my position was wrong. I repeated the movement. He slapped it again, a little harder. Seeing if I would get it.

A third time. Another shake of his head. Then he stopped.

He stood quietly, deep in thought. A slight smile crossed his face. Without a word, he pulled his hand back into his sleeve and waved the empty sleeve in front of me. He motioned for me to touch it.

There was nothing there.

No hand.

Only the sleeve. At that moment I understood: what is real may look empty. What looks empty may be real. At the time, I got it. The understanding why or how. much later.