[612] Which is that internal (ajjhattika) form (rūpa) that is not the sound base (saddāyatana)? … that is not the odour base (gandhāyatana)? … that is not the taste base (rasāyatana)? … that is not the tangible base (phoṭṭhabbāyatana)?
The eye base (cakkhāyatana) … the body base (kāyāyatana) — this is that internal form that is not the tangible base.
Which is that external (bāhira) form that is the tangible base?
The earth element (paṭhavī-dhātu) … this too is the tangible element (phoṭṭhabba-dhātu) — this is that external form that is the tangible base.
Which is that external form that is not the tangible base?
The form base (rūpāyatana) … edible food (kabaḷiṅkāra āhāra) — this is that external form that is not the tangible base.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.