Is it permissible for my friend to give money earned from selling books of sorcery and witchcraft—before his repentance—to a trustworthy merchant to invest it and allocate its returns to the poor and good causes, or must he dispose of it immediately?

It is forbidden to sell books of sorcery and charlatanism, and the money acquired from them is unlawful (haram). One must dispose of it by giving it to the poor and needy or spending it on public welfare, unless the acquirer was ignorant of the prohibition or was in need, in which case he may take from it what suffices his need. It is permissible to give the poor from this money an amount that can serve as capital for trade. It is obligatory to dispose of unlawful money immediately by removing it from one's possession. If the acquirer engaged in a forbidden transaction and the other party received the benefit, then that money paid in exchange for the unlawful benefit is not to be returned to him; rather, it should be spent on charitable causes. There is no objection to investing this money for the benefit of the poor if it leaves the acquirer's possession and he no longer has control over it.