坐禪三昧經 1.67

1.67

復次心止法中住觀。入息時五陰生滅異，出息時五陰生滅異，如是心亂便除却，一心思惟令觀增長，是名為觀法。

"Furthermore, resting the mind in the method of stopping, one contemplates: during inhalation, the arising and ceasing of the five aggregates are distinct; during exhalation, the arising and ceasing of the five aggregates are distinct. In this way, mental disturbance is eliminated, and with single-minded reflection one causes contemplation to increase; this is called the 'method of contemplation.'"