Treasury of the Eye of the True Dharma
Principles of Zazen
Studying Zen is zazen. For zazen, one should have a quiet place. Spread a thick sitting mat. Do not let in drafts or vapors; do not admit rain or dew. You should secure and maintain the spot where you place yourself. There are traces from the past of those who sat on a vajra [seat] or sat on a rock; they all spread a thick layer of grass to sit on. The place where you sit should be bright; it should not be dark either day or night. The technique is to keep it warm in winter and cool in summer.
Cast aside all involvements and discontinue the myriad affairs. Good is not thought of; evil is not thought of. It is not mind, intellect or consciousness; it is not thoughts, ideas or perceptions. Do not figure to make a buddha; slough off sitting or reclining.
You should be moderate in food and drink. Hold dear the passing days and nights, and take to zazen as though brushing a fire from your head. The Fifth Ancestor on Mt. Huangmei worked only at zazen, without any other other occupation.
During zazen, you should wear your kesa. Put down a cushion. The cushion is not placed completely under your crossed legs but only under the rear half, so that the mat is beneath the legs and the cushion beneath the spine. This is the way that all the buddhas and ancestors have sat during zazen.
Sit in either the half lotus or full lotus position. For the full lotus position, place your right foot on your left thigh and your left foot on your right thigh. The toes should be even with the thighs, not out of alignment. For the half lotus position, simply place your left foot on your right thigh.
Loosen your robe and underwaist, and arrange them properly. Place your right hand on your left foot and your left hand on your right hand. Put the tips of your thumbs together. With your hands in this position, place them against your body, so that that the joined thumb tips are aligned with your navel.
Straighten your body and sit erect. Do not lean to the left or right; do not bend forward or back. The ears should always be aligned with the shoulders, and the nose aligned with the navel. The tongue should be placed against the front of the palate. The breath should pass through the nose. The lips and teeth should be closed. The eyes should be open, neither too widely nor too narrowly.
Having thus regulated body and mind, take a breath and exhale fully. Sitting fixedly, think of not thinking. How do you think of not thinking? Nonthinking. This is the art of zazen.
Zazen is not the practice of dhyâna. It is the dharma gate of great ease and joy. It is undefiled practice and verification.
Treasury of the Eye of True Dharma, Principles of Zazen, Number 11.