[591] Which form (rūpa) is internal (ajjhattika) and invisible (anidassana)?
The eye sense base (cakkhāyatana) … the body sense base (kāyāyatana) — this is the form that is internal and invisible.
Which form is external (bāhira) and visible (sanidassana)?
The form sense base (rūpāyatana) — this is the form that is external and visible.
Which form is external and invisible?
The sound sense base (saddāyatana) … edible nutriment (kabaḷiṅkāro āhāro) — this is the form that is external and invisible.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.