It is best to start with the words of Sergeant Major Morris. Here is what he says about what the fakir said.
‘An old fakir put a spell on it. He was a very holy man and he wanted to show that fate ruled people’s lives, and that to interfere with fate only caused deep sadness. He put a spell on it so that three separate men could each have three wishes from it.’
At first the Whites thought that this was superstitious. But they were curious. So, in time, Mr. White made a wish. He wished for his house to be paid off. To his surprise he got the money, but it happened in an unexpected way. His son, Herbert, died at work.
Mrs. White could not bear the pain, and so she wished that she would have her son back. When she did this, there was a knock on the front door. Mr. White concluded that it must have been Herbet. However, since he was dead, Mr. White thought that the one knocking on the door might be a horrific version of Herbet. So, he wished it away.
Now as for the question of whether the Whites learned not to tamper with fate, I think they did. The fakir was successful.