[650] What is that form (rūpa) which is impinging (sappaṭigha) and a primary element (mahābhūta)?
The tangible sense base (phoṭṭhabbāyatana) — this is that form which is impinging and a primary element.
What is that form which is impinging and not a primary element?
The eye sense base (cakkhāyatana) … the taste sense base (rasāyatana) — this is that form which is impinging and not a primary element.
What is that form which is non-impinging (appaṭigha) and a primary element?
The water element (āpodhātu) — this is that form which is non-impinging and a primary element.
What is that form which is non-impinging and not a primary element?
The femininity faculty (itthindriya) … edible nutriment (kabaḷīkāro āhāro) — this is that form which is non-impinging and not a primary element.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.