坐禪三昧經 1.61

1.61

He answers: "It is not so! Because the internal mind stirs, there is an exhalation; once it has exited, it ceases. Because the nose and mouth draw in what is outside, there is an inhalation; because it enters, the breath ceases. There is neither that which carries it out nor that which carries it in. Furthermore, among the young, mature, and old: for the young, the inhalation is long; for the mature, inhalation and exhalation are equal; for the old, the exhalation is long. Therefore, they are not one single breath. Furthermore, wind arises from near the navel, resembling one another in continuous succession; the breath exits reaching the vicinity of the mouth and nose, and once it has exited, it ceases. It is like the wind in a bellows: when it opens, it ceases. If drawn in by the conditions of the mouth and nose, wind enters; it is produced from fresh conditions. For example, with a fan, because various conditions combine, there is wind. At this time, one knows that the inhalation and exhalation exist through causes and conditions, being deceptive, unreal, arising and ceasing, and anitya. Contemplating in this manner: the exhalation exists because it is drawn out through the conditions of the mouth and nose; the inhalation is produced because it is caused by the stirring of the mind; yet the deluded do not know this and think of it as 'my breath.'"