[131] What, on that occasion, is contact (phassa)?
That which on that occasion is contact, contacting (phusanā), the act of contacting (samphusanā), the state of being contacted (samphusitatta) — this, on that occasion, is contact.
What, on that occasion, is feeling (vedanā)?
That which on that occasion is mental (cetasika) neither-comfort-nor-discomfort (neva sātaṃ nāsātaṃ), born of contact with the corresponding mind-consciousness element (tajjā-manoviññāṇadhātu); the neither-painful-nor-pleasant (adukkhamasukha) experience born of mind-contact (cetosamphassa); the neither-painful-nor-pleasant feeling born of mind-contact — this, on that occasion, is feeling. …
What, on that occasion, is equanimity (upekkhā)?
That which on that occasion is mental neither-comfort-nor-discomfort; the neither-painful-nor-pleasant experience born of mind-contact; the neither-painful-nor-pleasant feeling born of mind-contact — this, on that occasion, is equanimity. …
What, on that occasion, is the faculty of equanimity (upekkhindriya)?
That which on that occasion is mental neither-comfort-nor-discomfort; the neither-painful-nor-pleasant experience born of mind-contact; the neither-painful-nor-pleasant feeling born of mind-contact — this, on that occasion, is the faculty of equanimity.
Or whatever other dependently arisen, immaterial phenomena (dhammā) there are on that occasion — these phenomena are wholesome.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.