長阿含經 25.p24

25.p24

The Buddha said, “Kāśyapa, this is world’s special teaching, that the teachings of ascetics and priests are difficult. Kāśyapa, even a laywoman can understand these teachings. Parting with clothing and going naked … tormenting one’s body with these countless hardships, a person still doesn’t understand their mind: ‘Am I angry or not … resentful or not … harmful or not?’ If someone knows these mental states, they aren’t named ascetics or priests. It’s because they don’t understand themselves that being an ascetic or priest is difficult.”