Moved again, it sends out more air. "A bellows is like an empty box for wind: when pumped, it can create a limitless amount of wind. The space between heaven and earth is likewise" empty. "Only in such an empty space can qi have free and fluent movement, and can wind and water enter to unleash tremendous amounts of energy.
虛而不屈，動而愈出」，「橐籥」是一種風箱，抽動後就可以源源不斷地生風，而天地之間本來就是「空」的，有這種空間，才能容許氣流自由流動，進而風生水起，產生極大的能量。