("To Live Is To Extend Ki" by Shinichi Tohei)
Student: What is the mind of void and calm, luminous awareness?
Chinul: What has just asked me this question is precisely your mind of void and calm, luminous awareness. Why not trace back its radiance rather than search for it outside? For your benefit I will now point straight to your original mind so that you can awaken to it. Clear your minds and listen to my words.
From morning until evening, all during the 12 periods of the day, during all your actions and activities -- whether seeing, hearing, laughing, talking, whether angry of happy, whether doing evil or good -- ultimately who is it that is able to perform all these actions? Speak! If you say that it is the physical body which is acting, then at the moment when a man's life comes to an end, even though the body has not yet decayed, how is it that the eyes cannot see, the ears cannot hear, the nose cannot smell, the tongue cannot talk, the hands cannot grasp, the feet cannot run?
You should know that what is capable of seeing, hearing, moving and acting has to be your original mind; it is not your physical body. Furthermore, the four elements which make up the physical body are by nature void; they are like images in a mirror of the moon's reflection in water. How can they be clear and constantly aware, always bright and never obscured -- and, upon activation, be able to put into operation sublime functions as numerous as the sands of the Ganges? For this reason it is said: "Drawing water and carrying firewood are spiritual powers and sublime functions."
There are many points at which to enter the noumenon. I will indicate one approach which will allow you to return to the source. Do you hear the sound of that crow cawing and that magpie calling?
Chinul: Trace them back and listen to your hearing-nature. Do you hear any sounds?
Student: At that place, sound and discrimination do not obtain.
Chinul: Marvelous! Marvelous! This is Avalokitesvara's method for entering the noumenon [exactly as explained in the Shurangama Sutra]. Let me ask you again. You said that sounds and discrimination do not obtain at that place. But since they do not obtain, isn't the hearing-nature just empty space at such a time?
Student: Originally it is not empty. It is always bright and never obscured.
Chinul: What is this essence which is not empty?
Student: Words cannot describe it.
See Tracing Back the Radiance: Chinul's Korean Way of Zen