What should the children of a Muslim man do if he invested in a company that sells alcohol and profited from selling its shares, and he has since passed away, knowing that they discovered his error? Can they give the money their father earned in charity or spend it on public utilities such as building roads, mosques, and schools? If the entire amount is exhausted, is it permissible for them to give charity from their own money?

The gist of the answer:

The children must donate the money their father earned from selling forbidden shares to public utilities (such as building roads and schools), with the intention of absolving their father of sin, not seeking closeness to Allah. This money should not be used to buy food or build mosques. It is permissible to donate the money itself or an equivalent amount from the children's own money, because the prohibition relates to the earning, not to the money itself.