[625] Which form (rūpa) is internal and not the water element (āpodhātu)?
The eye sense base (cakkhāyatana) … the body sense base — this is the form that is internal and not the water element.
Which form is external and the water element?
That which is water (āpo), the watery; viscidity (sineha), the viscid; the binding together of form — this is the form that is external and the water element.
Which form is external and not the water element?
The form sense base (rūpāyatana) … edible food (kabaḷīkāra āhāra) — this is the form that is external and not the water element.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.