“Bhikkhus, I will teach you the dyad. Listen to that….

“And what, bhikkhus, is the dyad? The eye and forms, the ear and sounds, the nose and odours, the tongue and tastes, the body and tactile objects, the mind and mental phenomena. This is called the dyad.

“If anyone, bhikkhus, should speak thus: ‘Having rejected this dyad, I shall make known another dyad’—that would be a mere empty boast on his part. If he was questioned he would not be able to reply and, further, he would meet with vexation. For what reason? Because, bhikkhus, that would not be within his domain.”