The Bodhisatta was once a teacher, famed across the land. He had five hundred students studying the sacred texts, and when finished they decided they were equal to him. In their pride they stopped coming to see him and doing their chores. One time after these students mocked the Bodhisatta, he asked them a question: “Time consumes all, even time itself. Who consumes the all-consumer?” The students were stumped and the Bodhisatta rebuked them as being like a jujube fruit; attractive on the outside, but lacking inside. He then told them he knew much that they didn’t and they should ponder the question for seven days.
When the students returned after a week they still had not figured out the answer, which was arahants. He told the students they have ears with holes in them, but no wisdom. Now knowing he was right they asked forgiveness and began serving him again as students should.
In the Lifetime of the Buddha
The five hundred students were earlier births of five hundred wandering ascetics who after having studied with the Buddha believed they had mastered all his teachings. Intoxicated with pride, they considered themselves equals. They stopped serving him and went out to find their own followers. One day the Buddha gave a sermon on the Succession of Causes along with the Eight Stages of Knowledge, and the ascetics did not understand any of it. They now realized nobody was as wise as the Buddha and they became humble again.
When the Buddha later heard some of his disciples discussing how the prideful ascetics had been put in their place, he told them this story so they knew it was not the first time he had done so.