Yogācārabhūmi-śāstra: Volume 34 (44)

Thus, through valid reasoning and the enhancement of practice, having firmly ascertained the characteristic of impermanence, one uninterruptedly enters into the contemplation of suffering. Reflecting thus: All these conditioned phenomena are impermanent. Because they are impermanent, they are definitely characterized by arising. Since these phenomena are characterized by arising, there is the suffering of birth. Since there is the suffering of birth, one should know that there is also the suffering of aging, sickness, and death; the suffering of association with the unpleasant; the suffering of separation from the pleasant; and the suffering of not obtaining what is desired. Thus, one initially enters the contemplation of suffering by way of undesirable phenomena. Then, further, within all the aggregates that are defiled and grasping, and which are capable of yielding pleasant feelings, one enters the contemplation of suffering by way of binding phenomena.

Explanation: Thus, through the principle of realization and the reason of enhancement in practice, having firmly ascertained the characteristic of impermanence in the mind, one thenceforth uninterruptedly enters the process of contemplating suffering. While cultivating the contemplation of suffering, one reflects thus: All these conditioned phenomena are impermanent. Because they are impermanent, they are definitely characterized by arising. Since these phenomena are characterized by arising, there is the suffering of birth. Since there is the suffering of birth, one should know that there is also the suffering of aging, sickness, and death; the suffering of association with the unpleasant; the suffering of separation from the pleasant; and the suffering of not obtaining what is desired. Thus, one initially enters the stage of contemplating suffering by way of undesirable phenomena. Then, further, within all the defiled aggregates characterized by grasping, which are capable of yielding pleasant feelings, one enters the contemplation of suffering by observing binding phenomena.

After realizing the impermanence of all conditioned phenomena through contemplative practice, the mind uninterruptedly contemplates the three kinds of suffering and the eight kinds of suffering, entering into the contemplation of suffering. Uninterruptedly entering the contemplation of suffering means that the mind faculty (manas) and the mental consciousness simultaneously firmly ascertain the impermanent dharmas, confirming that all conditioned phenomena are impermanent, and then together realize that all conditioned phenomena are suffering.