The full account of this lifetime is told in the Maha-Ummagga Jataka (#546), while the Sirimanda Jataka only relates this single incident from that story.
The Bodhisatta was once a king’s advisor. King Vedeha asked Senaka, his chief advisor, and the Bodhisatta, “Which is better, a wealthy fool or a poor wise man?” Senaka answered that wealth was the only thing that really mattered. People flock to rich men the way birds flock to a tree full of fruit, he said. The mighty Ganges River is nothing compared to the sea, and the words of rich men, no matter their truth, carry more weight than what a wise man says—just look at how the five advisors bow to the king. The Bodhisatta, on the other hand, chose wisdom, reasoning that fools who get wealth are struck by bad luck and commit sins, suffering in both this life and the next. Fools suffer shame and misery—a king would lose his throne without the help of wise advisors.
The Bodhisatta’s answer left Senaka speechless, like one who had used up all the food in his granary, and the king was so pleased he gave him a bull, an elephant, ten chariots pulled by thoroughbred horses, sixteen excellent villages, and a thousand cows.
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 that he’d also had perfect knowledge in the past.
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. Senaka was an earlier birth of Saccaka, a Jain who converted to be a disciple of the Buddha.