What is the ruling of Islamic law regarding a father accusing his son of disobedience (عقوق), expelling him from the home, and threatening that his siblings will also leave the home, due to the son's refusal to depart from the father's house, especially given that the father has married more than 20 times, neglected his children, and expelled some of them from his home?

Firstly, the father's right is great, and it is obligatory to honor him, whatever his condition may be.

Secondly, the majority of scholars hold that a sane, adult son who is not incapacitated is not entitled to maintenance from his father. However, the Hanbali school of thought maintains the obligation of a father to provide for his poor son, even if the son is healthy and strong. They also hold that it is obligatory to marry off a poor son who needs to marry.

Thirdly, if you are not in need, you are not entitled to maintenance or housing from your father. And for one who is in need, an adult capable of earning a living, he is also not entitled to that according to the majority of scholars. Therefore, it is permissible for the father to expel you from his house, and he would not be unjust to you.