[317] What on that occasion is contact (phassa)?
That which on that occasion is contact, contacting, being in contact, the state of being in contact — this on that occasion is contact.
What on that occasion is feeling (vedanā)?
That which on that occasion, born of contact with the corresponding mind-consciousness element (tajjā-manoviññāṇadhātu), is mental [experience] that is neither agreeable nor disagreeable; the neither-painful-nor-pleasant 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 [experience] that is neither agreeable nor disagreeable; 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 [experience] that is neither agreeable nor disagreeable; 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 unwholesome.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.