摩訶止觀 2.6

2.6

For the body, permission is given for constantly sitting, while walking, standing, and lying down are prohibited. One may be among an assembly, but being alone is even better. Reside in a quiet room or an empty, quiet place, free from noisy bustle, setting up a single corded bed with no other seat beside it. Take ninety days as one period. Sit upright in the lotus posture, with neck and spine erect and straight, without moving, shaking, drooping, or leaning, taking sitting as one's vow. The ribs must not touch the bed, much less lying like a corpse, sporting, or idling standing. Except for walking meditation, eating, and urinating or defecating, face the direction of a single Buddha, sitting upright and directly facing it, continuously from moment to moment without a moment's lapse. As for what is permitted, sit exclusively; as for what is prohibited, do not violate it. Do not deceive the Buddhas, do not betray your own mind, and do not deceive sentient beings.