In Vietnam there was a rich man who shrewdly increased his wealth through loans with usurious interest.

One day, intending to take anything of value he could from a poor, hard-working man who’s payment was due, the rich usurer walked to the poor man’s hut. No one was home but a boy, entertaining himself with spinning sticks and stones.

“Where are your parents, Boy?” the man asked.

“Father is cutting living trees and planting dead ones,” the boy said, his voice solemn. “Mother is selling the wind to buy the moon.”

Of course the rich man recognized a riddle when he heard one, but he could not think of the answer.

Being who he was, he expected the boy to answer when asked, but the boy went on playing as if he’d heard nothing. Finally the usurer was so angry he promised to cancel the family’s debts if the boy would only speak the answer to his riddle.

This interested the boy.

“Do you really mean it? Would you really cancel the whole debt?”

“I swear by Heaven and Earth,” said the usurer, thinking how easily he could get out of the swearing.

“No,” said the boy. “Heaven and earth cannot speak. We must have a living witness.”

Just then a fly buzzed past, then returned to light upon the usurer’s staff.

“Will this living creature suffice?” asked the man.

“Yes, ” said the boy. “I will agree to the witness. For the price of our debt:

“My father has gone to cut bamboo to make a fence for the man who hired him. My father is quite sensible for planting dead trees. It is good, honest work.

My mother has gone to the village to sell fans in order to buy lamp oil. Surely you must agree that is selling the wind to buy the moon.”

The usurer chuckled to himself, figuring he had bought the answer to a hard riddle for nothing more than a lie.

The next time he returned both parents were home, and the usurer demanded payment. The frightened peasants begged for more time, and the commotion woke the boy. He quickly told his parents of the riddle and the bargain he’d made. When the usurer denied it the case was brought before the local mandarin where the usurer insisted he had never spoken to the boy.

The mandarin was a fair, kind man, but when faced with the word of a man against the word of a boy, he could only say he was sorry, but word to word he could not forgive the debt.

“It is too bad, child, that you did not take the precaution of having a witness.”

“But we did, honorable one. There was a fly. He landed on the face of this man!”

“Little liar! He was no closer than my staff.” The usurer clapped his hand over his mouth, but the damage had been done: The mandarin was convinced the two had spoken.

Having found one lie in the usurer’s mouth already, the official ruled in favor of the boy and his family, and the usurer was forced to forgive the entire debt.