The Jataka, Vol. II, tr. by W.H.D. Rouse, , at sacred-texts.com
"Time all consumes," etc.--This is a story told by the Master while he stayed near Ukkaṭṭhā, in the Subhagavana Park, in connexion with the Chapter on the Succession of Causes.
At that time, it is said, five hundred brahmins who had mastered the three Vedas, having embraced salvation, studied the Three Piṭakas. These learnt, they became intoxicated with pride, thinking to themselves--"The Supreme Buddha knows just the Three Piṭakas, and we know them too. So what is the difference between us?" They discontinued their waiting upon the Buddha, and went about with an equal following of their own.
One day the Master, when these men were seated before him, repeated the Chapter on the Succession of Causes, and adorned it with the Eight Stages of Knowledge. They did not understand a word. The thought came into their mind--"Here we have been believing that there were none so wise as we, and of this we understand nothing. There is none so wise as the Buddhas: O the excellence of the Buddhas!" After this they were humbled, as quiet as serpents with their fangs extracted.
When the Master had stayed as long as he wished in Ukkaṭṭhā, he departed to Vesāli; and at Gotama's shrine he repeated the Chapter on Gotama. There was a quaking of a thousand worlds! Hearing this, these Brothers became saints.
But however, after the Master had finished repeating the Chapter on the Succession of Causes, during his visit to Ukkaṭṭhā  the Brethren discussed the whole affair in the Hall of Truth. "How great is the power of the Buddhas, friend! Why, these brahmin mendicants, who used to be so drunk with pride, have been humbled by the lesson on the Succession of Causes!" The Master entered and asked what their talk was about. They told him. He said, "Brethren, this is not the first time that I have humbled these men, who used to carry their heads so high with pride; I did the same before." And then he told them a tale of the olden time.
Once upon a time, when Brahmadatta reigned in Benares, the Bodhisatta was born a brahmin; who when he grew up, and mastered the Three Vedas, became a far-famed teacher, and instructed five hundred pupils in sacred verses. These five hundred, having given their best energy to their work, and perfected their learning, said within themselves,
"We know as much as our teacher: there is no difference."
Proud and stubborn, they would not come before their teacher's face, nor do their round of duty.
One day, they saw their master seated beneath a jujube tree; and desiring to mock him, they tapped upon the tree with their fingers. "A worthless tree!" said they.
The Bodhisatta observed that they were mocking him. "My pupils," he said, "I will ask you a question."
They were delighted. "Speak on," said they, "we will answer."
Their teacher asked the question by repeating the first stanza:--
 The youths listened to the problem; but not one amongst them could answer it. Then said the Bodhisatta,
"Do not imagine that this question is in the Three Vedas. You imagine that you know all that I know, and so you act like the jujube tree 2. You don't know that I know a great deal which is unknown to you. Leave me now: I give you seven days--think over this question for so long."
So they made salutation, and departed each to his own house. There for a week they pondered, yet they could make neither head nor tail of the problem. On the seventh day, they came to their teacher, and greeted him, sitting down.
"Well, ye of auspicious speech, have you solved the question?"
"No, we have not," said they.
Again the Bodhisatta spoke in reproof, uttering the second stanza:--
"Fools are ye," he went on, rebuking the youths: "ye have ears with holes in them, but not wisdom;" and he solved the problem.  They listened. "Ah," said they, "great are our Teachers!" and they craved his pardon, and quenching their pride they waited upon the Bodhisatta.
When the Master had ended this discourse, he identified the Birth: "At that time these Brothers were the five hundred pupils; and I myself was their teacher."
181:1 Kālaghaso, the 'consumer of time,' is he who, by destroying the thirst for existence, so lives as not to be born again (Scholiast's explanation).
181:2 The jujube fruit is often contrasted with the cocoa nut, as being only externally pleasing, see Hitop. i. 95.