Take The pearl From The Dragon--Tan Li De Zhu

The Chinese of Take The pearl From The Dragon--Tan Li De Zhu is 探骊得珠, and Pin Yin liáng shàng jūn zǐ. 

Once upon a time, there dwelt a father and son by the Yellow River who got their living by weaving mat. Hard as they worked, they could only make ends meet.
One day in the summer, the son felt very tired and hot after having worked for hours in the sun. He took off his clothes, jumping into the river and cheerfully swimming up and down. Suddenly he saw some golden light shining in the deep water which reminded him of the old folk tale that there were numberless treasures on the bottom of the Yellow River.

So the son dove, as deeply as he could, towards the light. Just before he used out of air in his lung, he finally reached the bottom and found out the shining thing was a beautiful pearl. Wasting no time, he grabbed it into his hand and then swim up to the top quickly.

When the excited son presented the pearl to his father, the old man was terrified out of his mind. After a while, he exclaimed:" A disaster is imminent, Son. A pearl like this must have been in the deep river, and under the chin of the black dragon. The black dragon must have been sleeping when you were taking the pearl. Once it awakes up, it will certainly come recapture the pearl. At that time, you will be torn into pieces. Thus, you'd better smash the pearl with a stone."

Background and Writer Comment:

This Chinese idiom story is from "Lie Yu kou (列御寇)", an article of Zhuang Zi, a great philosopher in ancient China and one of the main founders of Taoism.

According to Zhuang Zi, a man had an interview with the king of the state of Song, and was presented by the king with ten carriages; when he saw Zhuang Zi, he boastfully showed off the carriages; so Zhuang Zi told him this story and at the end commented: " the state of Song is deeper than the yellow river, and its king is fiercer than the Black Dragon. The king must have been 'sleeping' when you got the carriages. Once he awakes up, you will be dead for sure."

The original intention of Zhuang Zi is to use this story to illustrate that do not be bewildered by current happiness, and be cautious of the future disaster.

Later, people derived the idiom of "Take The pearl From The Dragon--Tan Li De Zhu" form this story, but they gave it a totally different meaning: To write and bring out important points from a mass of facts as the son in this story who directly took the pearl from the black dragon without wasting any time or making any detour.

There are  other two stories related to this one:  "Dress And Feed The Sacrificial Bull--Xi Niu Yi Shi " and "You Get So Many Carriages Just By Licking The king's Piles"