Saḷāyatanavibhaṅgasutta

Suttapiṭaka · Majjhimanikāya · Vol. 14 · Section 619

[619] "'The six internal sense bases (āyatana) should be understood' — so it was said. And in dependence on what was this said? The eye base, the ear base, the nose base, the tongue base, the body base, and the mind base. So it was with reference to this that it was said: 'The six internal sense bases should be understood.'"

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.

This passage also appears in 1 other place

Vol. 14 · Section 812 — Chachakkasutta