Saññāaññāṇa sutta: Not Knowing Perception

At Sāvatthī.

Then the wanderer Vacchagotta said to the Buddha:

“What is the cause, worthy Gotama, what is the reason why these various misconceptions arise in the world? …”

“Vaccha, it is because of not knowing perception, its origin, its cessation, and the practice that leads to its cessation …”