Precious Jewel story

Once upon a time, there lived an old man with his three sons. They lived together in happiness and prosperity.

One day, the father got sick and no one took care of him except the youngest son, who took care of him until he passed away.

Not long after that, the youngest son dreamt that his father had hidden for him the inheritance and informed him of its location.

He told his brothers about the dream and they all headed towards that place. For his surprise, his brothers took almost all the money and jewels and kept only a small amount of money for him. He felt very depressed.

Someday, while the little brother was going home, he met an old man who was trying to sell a big fish. He bought it for only one dirham.

At home, he gave the fish to his wife and asked her to cook it. When she cut the fish, she found a big precious jewel inside! They sold it and became very rich.

What is the moral of this story?