Two men were crossing the desert together, each carrying his own provisions. One of them — the cunning one — proposed that they first eat all the provisions of his companion and save their own for later. The trusting companion agreed.
When the generous man's food was gone, the cunning one refused to share his own. He grabbed his supplies and ran.
The abandoned traveler was stranded. He climbed a small mountain looking for food and found only herbs. Afraid of wild animals on the open ground, he climbed high into a tree and settled among its branches for the night.
Below him, two shedim — desert demons — came strolling through the grove in the dark, dragging a limp body behind them. The traveler, frozen in the branches, recognized the body at once: it was the cunning companion who had abandoned him. The demons, unaware of the watcher above, slaughtered the body, lit a fire, and roasted it.
As they ate, they talked. The first demon said casually to the other, "You know, the leaves of this very tree can heal any illness." The second demon nodded and added, "And the daughter of the king of Alexandria is insane. The only cure is the blood of a spotted dog mixed with the blood of a tiger."
They finished their meal and departed.
When dawn came, the traveler climbed down shaking. He gathered a large bundle of leaves from the tree and set out.
Town by town, he began to heal the sick. Each cure increased his reputation and his purse. He grew rich. Eventually his reputation reached Alexandria, and the king's court summoned him to attempt what no physician had managed — to cure the princess.
He remembered the second demon's words. He procured the blood of a spotted dog and the blood of a tiger, mixed them, administered the mixture. The princess was healed.
The king gave him his daughter in marriage and a great fortune besides (Gaster, Exempla No. 447).
The story plays like a folk tale, but its sages' lesson is dry and precise. The cunning traveler's food ran out exactly when his cunning did. The abandoned traveler's only resource was an upward climb and an open ear, and those two were enough. Heaven gives information to the one who is listening. And it gives punishment to the one who has grabbed his supplies and run.