Saṁyutta Nikāya 22.127 13.
Dutiyasamudayadhammasutta
Avijjāvagga Dutiyasamudayadhammasutta Ekaṁ samayaṁ āyasmā ca sāriputto āyasmā ca mahākoṭṭhiko bārāṇasiyaṁ viharanti isipatane migadāye.
At one time, Venerable Sāriputta and Venerable Mahākoṭṭhika were staying near Benares in the Deer Park at Isipatana.
Atha kho āyasmā mahākoṭṭhiko sāyanhasamayaṁ paṭisallānā vuṭṭhito …pe… ekamantaṁ nisinno kho āyasmā mahākoṭṭhiko āyasmantaṁ sāriputtaṁ etadavoca: “‘avijjā, avijjā’ti, āvuso sāriputta, vuccati.
Then, in the late afternoon, Venerable Mahākoṭṭhika came out of retreat, approached Venerable Sāriputta, and sat down to one side.
Venerable Mahākoṭṭhika said to Venerable Sāriputta: Ignorance, ignorance, they say, friend Sāriputta.
Katamā nu kho, āvuso, avijjā; kittāvatā ca avijjāgato hotī”ti?
But what is ignorance, and how is one mired in ignorance?
“Idhāvuso assutavā puthujjano samudayadhammaṁ rūpaṁ ‘samudayadhammaṁ rūpan’ti yathābhūtaṁ nappajānāti; vayadhammaṁ rūpaṁ …pe…
Here, friend, an uneducated ordinary person does not truly know form as a phenomenon that arises and passes away.
‘samudayavayadhammaṁ rūpan’ti yathābhūtaṁ nappajānāti. Samudayadhammaṁ vedanaṁ …pe… vayadhammaṁ vedanaṁ …pe…
They do not truly know feeling as a phenomenon that arises and passes away.
‘samudayavayadhammā vedanā’ti yathābhūtaṁ nappajānāti. Samudayadhammaṁ saññaṁ …pe… samudayadhamme saṅkhāre …pe… vayadhamme saṅkhāre …pe…
They do not truly know perception as a phenomenon that arises and passes away.
samudayavayadhamme saṅkhāre ‘samudayavayadhammā saṅkhārā’ti yathābhūtaṁ nappajānāti.
They do not truly know choices as phenomena that arise and pass away.
Samudayadhammaṁ viññāṇaṁ …pe… samudayavayadhammaṁ viññāṇaṁ ‘samudayavayadhammaṁ viññāṇan’ti yathābhūtaṁ nappajānāti. Ayaṁ vuccati, āvuso, avijjā; ettāvatā ca avijjāgato hotī”ti. Dutiyaṁ.
They do not truly know consciousness as a phenomenon that arises and passes away.
This is called ignorance, friend, and this is how one is mired in ignorance.