Ma'mar ibn Taa'us narrates from his father who said, "A man who had four sons became quite ill. One of the sons said to the others, ‘Either you care for our father during his illness and you will then not receive anything from his inheritance or I will care for him and I will not receive anything from his inheritance.'
They replied, "You may take care of him and you will then not receive anything from his estate."
The son then saw to the father until the father passed away. He was not given anything from the inheritance as agreed.
One night his father came to him in a dream and he was told to go to a certain place where he would find a hundred dinaars. He asked whether the money had barakah. He was told that it had no barakah. In the morning he related the dream to his wife who said, "Take the money. The barakah of the money would menifest in such a way that we would be able to use it to clothe ourselves and purchase things to allow us to live." The husband, however, did not accept her advice.
The next night he had the same dream. He was told to go to a certain place where he would find ten dinaars. Upon questioning he was again told that the money did not have barakah. In the morning he related the dream to his wife who again advised him to take the money. He again refused.
On the third night again he was told to proceed to a place where he would find one dinaar. This time, however, he was told that it had barakah. In the morning he went to the place he had been directed to and took the dinaar. At the market he met a man selling two fish for a dinaar. He bought the fish and came home. When he cut open the fish he found a pearl in the stamach of each of the two fish. Nobody had ever seen the like of the pearls.
Now, the king of the time wanted to purchase a pearl. The type he was looking for could only be found with this man. He sold one of the pearls to the king for thirty mule-loads of gold. When the king saw the pearl he remarked, "Search for another similar pearl as this pearl does not look right on its own. Even if you have to pay double its price, find it!"
The kings men again came to the man and asked, "Do you have another like it? We are prepared to pay you double the amount we paid you for the first one."
The man asked in amazement, "Will you really?"
"Yes, they answered."
He handed them the pearl and they paid him the agreed sum. (Hilyatul Awliya)

Lessons
1. A little bit of patience in acquiring halaal wealth goes a long way. Wise is that person who realises that little wealth that has barakah is far better than a large quantity without barakah. The philosophy of 'making a quick buck' without any consideration of the Shar'i validity is short-sighted and ruinous in the long term.
2. Taking care of parents is a fundamental teaching of Islam and brings immense rewards.