[363] Therein, which are the wholesome roots (kusalamūla)? Non-greed (alobha), non-hatred (adosa), non-delusion (amoha) … These are called the wholesome roots.
Therein, which is the volitional formation (saṅkhāra) with the wholesome roots as condition? That which is volition (cetanā), intending (sañcetanā), the state of having intended (sañcetayitatta) — this is called the volitional formation with the wholesome roots as condition. …
Therein, which is the feeling (vedanā) with contact (phassa) as condition? That which is mental neither-pleasure nor pain; the neither-painful-nor-pleasant experiencing born of mind-contact (cetosamphassa); the neither-painful-nor-pleasant feeling born of mind-contact — this is called the feeling with contact as condition. …
Therefore it is said: "Thus is the origin of this whole mass of suffering (dukkha)."
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.