Raikwa of the Cart - Chandogya IV 1 & 2

I've done a fairly free translation here, as the key thing is the story. It's a kind of fairy tale, but with a lot to consider. The story is the first in section IV of the Upanishad; there are more like this to follow, but none perhaps so unusual.

Once upon a time there was a descendant of Jaanashruta, the grandson of his son, who offered gifts respectfully, gave alms in plenty, and fed many. He had rest-houses built everywhere, with the thought, "I will feed the people everywhere". He was called Jaanashruti Pautraayana.

Then once, two swans came flying in the night to where Jaanashruti slept. He woke up when he heard their wings, and was astonished to hear them speak. This is what they said.

The first swan spoke mockingly to the other, "You are far-sighted indeed! Do you not see how the lustrous fame of Jaanashruti spreads everywhere like the light of heaven. Don't touch it - it will burn you!"
The second replied, as quick as anything, "What, who is this individual you are speaking about, as though he were the equal of Raikwa of the Cart?" The first said, "Who is this Raikwa of the Cart?"
"Just as in a game of dice, the highest throw wins over all the others, so all virtuous deeds people may do are outdone by Raikwa. Only someone who knows what Raikwa knows, is like Raikwa. That is who I am talking about."

Jaanashruti overheard this conversation, and as soon as he got up the next morning, he spoke to his charioteer bitterly. "You have praised me in the past, as though I were the equal of Raikwa of the Cart". The charioteer asked in surprise, "What kind of a man is this Raikwa of the Cart?" And Jaanashruti repeated what the swan had said: "Just as in a game of dice, the highest throw wins over all the others, so all virtuous deeds people may do are outdone by Raikwa. Only someone who knows what Raikwa knows, is like Raikwa. That is who I am talking about."

The charioteer was ordered by the king to search everywhere for the great Raikwa, and he searched through all the towns and villages for a king or nobleman of this name. He returned without success. When he reported this to the king, he was told: "Then look for him in the places that a holy man would live!" The charioteer wandered through the forests and lonely places, but nowhere could he find Raikwa.

At last he sat down, discouraged and worn-out, leaning against an old cartwheel, and next to him he saw a man, lying underneath the cart, busy scratching himself. The charioteer was amazed, and said, "Are you, Sir, Raikwa of the Cart?" The man replied, "I am indeed", and having heard that the charioteer returned to tell the king what he had found.

Jaanashruti Pautraayana gathered six hundred head of cattle, a gold necklace, a chariot drawn by she-mules, and travelled to the place.
"O Raikwa!" he said, "Here are six hundred heads of cattle, a fine gold necklace, and a chariot drawn by she-mules. Sir, please teach me about that deity on whom you meditate."
But Raikwa was unimpressed at this offer, and replied scornfully: "Peasant! Keep your chariot, necklace and cows!"

Jaanashruti returned once more, this time with a thousand head of cattle, a gold necklace, a chariot drawn by she-mules, and his daughter. He offered all this to Raikwa, together with the village where he lived, asking once more, "please teach me, Sir".
Gazing on Jaanashruti's daughter's face, Raikwa said, "Well, peasant, you have brought these; and through this very face you will make me speak". And to him he imparted his knowledge.

Chandogya IV, I-II

The king has to give what is most precious to him to get the knowledge.  Raikwa is neither a brahmana nor a kshatriya, nor does he do good deeds like the king, but his knowledge ("the deity on whom you meditate") is more valuable than anything.  Also interesting is the role of the daughter: the feminine is what brings the secret knowledge into the open.