Now, this being the case, in this method, what is meant by sitting in meditation? In this method, to sit means to be free from all obstacles, and externally not to allow thoughts to rise from the mind over any sphere of objects. To meditate means to realize the imperturbability of one's original nature. What is meant by meditation and calmness? Meditation means to be free from all characters externally; calmness means to be unperturbed internally. If there are characters outside and the inner mind is not disturbed, one's original nature is naturally pure and calm. It is only because of the spheres of objects that there is contact, and contact leads to perturbation. There is calmness when one is free from characters and is not perturbed. There is meditation when one is externally free from characters, and there is calmness when one is internally undisturbed. Meditation and calmness mean that external meditation is attained and internal calmness is achieved.

(Hui Neng)