What is the ruling of Islamic law on spending on a stingy father who possesses wealth, and is it permissible for the son to leave his family home to get married while continuing to support them?

You are not obligated to spend on your father if he has sufficient means. However, kindness and benevolence towards him are required, even if he mistreats you; his ill-treatment does not prevent you from being benevolent towards him. A father is not obligated to spend on his children who are financially independent. A divorced woman is entitled to maintenance during her iddah (definition) (waiting period) unless she is disobedient (nashiz) and not pregnant; she is not entitled to maintenance after the iddah. An adult of sound mind has the right to live independently of his parents. Your wife has the right to a separate dwelling and is not obligated to live with your relatives. You must visit your parents, be kind to them, and maintain ties of kinship. Among your greatest acts of kindness towards your father is striving to reform him and supplicating for him, and your warning against disobedience due to him.