The full account of this lifetime is told in the Maha-Ummagga Jataka (#546), while the Gadrabha-Panha Jataka only relates this single incident from that story.
The Bodhisatta was once a king’s advisor. As a seven-year-old boy, he was already incomparably smart, and King Vedeha invited him and his father to the palace with the intention of hiring him as an advisor. As the Bodhisatta traveled in a magnificent chariot to the city, he saw a donkey along the road and had a strong man tie its mouth shut to prevent it making noise, put it in a bag, and carry it to the palace over his shoulder. The Bodhisatta entered the city to great applause and was warmly welcomed by the king, who told him to take a seat wherever he pleased. The Bodhisatta looked at his father who, as he’d been instructed, stood up and said, “Wise son, take my seat.” He did so, and the king’s four advisors laughed loudly and cried out, “This is the boy renown as wise? Only a blind fool would disrespect his father like this.”
King Vedeha was visibly upset by the Bodhisatta’s behavior. “My lord,” the Bodhisatta asked, “Do you think the father is always better than the sons?” The king answered yes, so the Bodhisatta released the donkey and asked the king its worth. “At most eight coins,” he answered. Then the Bodhisatta asked the price of a mule born to this donkey and a thoroughbred horse. “It would be priceless.” Thus the Bodhisatta disproved the king’s assertion that the father is always better than the offspring, and this made the king happy again. Then, to hammer home the point, he mocked, “If you still believe the father is always better than the son, hire my father as your advisor instead of me.”
The room erupted in praise and applause—there was snapping of fingers and waving of a thousand scarves—except from the four advisors who were upset at having been so thoroughly outdone. King Vedeha not only made the Bodhisatta his fifth advisor, he adopted him as his own son, giving the Bodhisatta’s parents command over their village and many ornaments in exchange.
In the Lifetime of the Buddha
One day some of the Buddha’s disciples were discussing his supreme wisdom. In particular, how he had humbled and converted a vast multitude of brahmins, ascetics, thieves, goblins, gods, and more. When the Buddha heard them talking about it, he told them this story so they knew he’d had perfect knowledge in the past too.
King Vedeha was an earlier birth of Laludayi, an elder disciple of the Buddha who was so shy that he could not speak when around more than a single other person, and he often said one thing when he meant another. The king’s chief advisor was an earlier birth of Saccaka, a Jain who converted to be a disciple of the Buddha, and the other three advisors were Potthapada, Ambattha, and Pilotika, three ascetics who respected the Buddha.