[328] On one occasion the Venerable Sāriputta and the Venerable Mahākoṭṭhita were dwelling at Bārāṇasī, in the Deer Park at Isipatana. Then the Venerable Sāriputta … Seated to one side, the Venerable Sāriputta said this to the Venerable Mahākoṭṭhita: "'Ignorance (avijjā), ignorance,' it is said, friend Koṭṭhita. What now, friend, is ignorance, and in what way is one immersed in ignorance?"
"Here, friend, the uninstructed worldling does not understand as it really is (yathābhūta) the gratification, the danger, and the escape in the case of form (rūpa); he does not understand as it really is the gratification, the danger, and the escape in the case of feeling (vedanā) … of perception (saññā) … of volitional formations (saṅkhārā) … of consciousness (viññāṇa). This, friend, is called ignorance, and in this way one is immersed in ignorance."
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.