What is the ruling of Islamic law regarding a father who demands money from his employed children despite his financial comfort, and refuses to spend on the household, knowing that he was formerly an alcoholic then repented and became religious?

It is not permissible for a father to treat his children with harshness or injustice. However, if he does so, his right to dutifulness from them is not forfeited. Financial support for a wealthy father is not obligatory, but he should be connected through financial means in a way that does not harm the children. The mother's financial support is obligatory on the father, and there is a difference of opinion regarding her medical treatment. We advise you to be dutiful to your father and to connect with him financially, to advise him with wisdom and good admonition, and to seek assistance from someone who holds a position of respect with him.