Father must have money and can provide for his family. He Wouldn't act that way if they don't have enough. Or maybe the father is really a disciplinarian and wanted the boy to stop gambling as well.
A boy having that much in Nigeria can live a life on his own afaik. Fathers can see where this boy is heading and he'll have a say in the family which a father will not like.
I am certain that the father is very religious to let off that much money especially that this incident happened in Nigeria. Even if he cannot provide enough for his family or even if they are facing financial difficulties, he wouldn’t accept that money because it is forbidden in his religion. I know many people who would do the same thing as I grew up in a religious family and community and I completely understand that father.
Now it is up to the boy whether he wants to heed his dad's words and continue living in his house, or start his own life and accept that money. Personally I would forget about the gambling money since it wasnt earned through hard work or anything productive. I would prioritize maintaining a strong relationship with my father no matter what.