The Buddha shares a reflection on the three characteristics of impermanence, suffering (discontentment) and not-self for the five aggregates of form, feeling, perception, formations, and consciousness.
Yadanicca sutta - That Which is Impermanent
At Sāvatthi.
"Form, bhikkhus, is impermanent. What is impermanent is suffering; what is suffering is not-self; what is not-self should be seen as it truly is with correct wisdom: 'This is not mine, I am not this, this is not my self.'
Feeling is impermanent. What is impermanent is suffering; what is suffering is not-self; what is not-self should be seen as it truly is with correct wisdom: 'This is not mine, I am not this, this is not my self.'
Perception is impermanent. What is impermanent is suffering; what is suffering is not-self; what is not-self should be seen as it truly is with correct wisdom: 'This is not mine, I am not this, this is not my self.'
Formations are impermanent. What is impermanent is suffering; what is suffering is not-self; what is not-self should be seen as it truly is with correct wisdom: 'This is not mine, I am not this, this is not my self.'
Consciousness is impermanent. What is impermanent is suffering; what is suffering is not-self; what is not-self should be seen as it truly is with correct wisdom: 'This is not mine, I am not this, this is not my self.'
Seeing thus, the wise bhikkhu here comprehends: 'There is no further continuation of this state of being.'"