[617] Which is that form (rūpa) that is external, not the eye faculty (cakkhundriya)?
The form base (rūpāyatana) … edible nutriment (kabaḷīkāra āhāra) — this is that form that is external, not the eye faculty.
Which is that form that is internal, the eye faculty?
The eye (cakkhu) that is the sensitivity (pasāda) derived from the four primary elements (mahābhūta) … "this, too, is an empty village" — this is that form that is internal, the eye faculty.
Which is that form that is internal, not the eye faculty?
The ear base (sotāyatana) … the body base (kāyāyatana) — this is that form that is internal, not the eye faculty.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.