Seated to one side, that monk said to the Buddha:
“Bhante, they speak of this thing called ‘ignorance’. What is ignorance? And how is an ignorant person defined?”
“Monk, not understanding about suffering, not understanding about the origin of suffering, not understanding about the end of suffering, and not understanding about the path that leads to the end of suffering. This is called ignorance. And this is how an ignorant person is defined.
“Therefore, monks, you should make an effort to understand …”