Khandasaṃyutta, Saṃyutta Nikāya, Pali Canon

(5) Concentration, (6) Seclusion

(5) Wise ones, develop concentration. One who is concentrated understands things as they really are. (6) Wise
ones, make an exertion in seclusion. One who makes an exertion in seclusion understands things as they really are. What what does one understand as it really is? The origin and passing away of [the 5 aggregates: ] 1. form, 2. contact/consciousness, 3. perception, 4. feeling/sensations and 5. sankhara/volitional formations. And what, wise ones, is the origin of the 5 aggregates? One seeks delight in form, contact/consciousness with form, perception of form, feelings/sensations resulting from form, and sankharas/volitional formations reacting to form. One welcomes it, and remains holding to it. As a consequence of this, delight arises. Delight in form is clinging. With one’s clinging as condition, existence comes to be; with existence as condition, birth; with birth as condition, aging-and-death, sorrow, lamentation, pain, displeasure, and despair come to be. Such is the origin of this whole mass of suffering. This is the origin of the 5 aggregates : 1. form, 2. contact/consciousness, 3. perception, 4. feeling/sensations, and 5. sankhara/volitional formations. What what is the passing away of the 5 aggregates? One does not seek delight in form, does not welcome it, does not remain holding to it. As a consequence of this, delight in form ceases. With the cessation of delight comes cessation of clinging, with cessation of clinging, cessation of existence… Such is the cessation of this whole mass of suffering.

(7) Agitation through Clinging

How, wise ones, is there agitation through clinging? Here, the uninstructed worldling, who is not a seer of the noble ones and is unskilled and undisciplined in their Dharma, regards form as self, or self as possessing form, or form as in self, or self as in form. That form of one’s changes or alters. With the change and alteration of form, one’s consciousness becomes preoccupied with the change of form. Agitation and a constellation of mental states born of preoccupation with the change in form remain obsessing one’s mind. Because one’s mind is obsessed, one becomes frightened, distressed and anxious, and through clinging one becomes agitated. One regards [ the 5 aggregates: ] 1. form, 2. contact/consciousness, 3. perception, 4. feeling/sensations, and 5. sankhara/volitional formations, as self or self as possessing them, or them as in self or self as in them… Through clinging to the aggregates one becomes agitated. In such a way, there is agitation through clinging. And how, wise ones, is there non-agitation through non-clinging? Here, the instructed noble disciple, who is a seer of the noble ones, and is skilled and disciplined in their Dharma, does not regard form as self, or self as possessing form, or form as in self, or self as in form. That form changes and alters. Despite the change and alteration of form, one’s consciousness does not become preoccupied with the change in form. No agitation and constellation of mental states is born out of preoccupation with the change in form that remains obsessing one’s mind. Because one’s mind is not obsessed, one is not frightened, distressed of anxious, and through non-clinging one does not become agitated. Such a wise one does not regard the 5 aggregates as self, or self as possessing them, of them as in self or self as in them… and through non-clinging one
does not become agitated. It is in this way that there is non-agitation through non-clinging.