There were once two brothers who both served as soldiers; one was rich, and the other poor. To escape poverty, the poor brother became a farmer. He sowed turnip seeds, and one grew exceptionally large—so large it filled a cart and required two oxen to pull it.
Unsure what to do with such a giant turnip, the farmer decided to present it to the King. The King, amazed by the monstrous vegetable, asked if the farmer was a "luck-child." The farmer explained he was a poor soldier turned farmer, forgotten by all while his rich brother was well-known.
Moved by compassion, the King bestowed upon the farmer great wealth—gold, lands, meadows, and herds—making him richer than his brother.
When the rich brother heard how a single turnip had brought such fortune, he grew envious. He took gold and horses to the King, expecting an even greater reward. However, the King declared he had nothing more rare or excellent to give than the great turnip itself. Thus, the rich brother was forced to take the turnip home.
Furious, the rich brother resolved to kill his sibling. He hired murderers to ambush him, luring him with a tale of hidden treasure. On the way, the assassins attacked, bound the poor brother, and were about to hang him when they heard approaching sounds. In panic, they stuffed him into a sack, hung it on a tree, and fled.
The poor brother managed to poke his head out of the sack. Soon, a traveling student rode by, singing joyfully. From the tree, the brother called out, claiming to sit in the "Sack of Wisdom," where he was rapidly learning all the world's knowledge.
Intrigued by the promise of wisdom, the student begged to enter the sack. After some pretended reluctance, the brother agreed, on condition the student lower the sack and free him first. Once free, the brother quickly put the student into the sack, hoisted him up the tree, and rode off on his horse, leaving the student to "gain wisdom." An hour later, he sent someone to release the student.