Ruling on attending the wedding feast of one who deals in riba

Our sister asks and says: Is it permissible for a Muslim to accept the invitation of a usurer who deals in what is forbidden, who has invited him to a wedding feast, while he is aware of this?
Answer: If the inviter is one who engages in what is forbidden, and his food and drink come from what is forbidden, then he should not be answered; because this involves negligence and proceeding to something of what is forbidden. However, if he has another source of income from both what is forbidden and what is lawful, then it is permissible; because you do not know whether what is served is forbidden or lawful. So, those with various sources of income that include both lawful and unlawful, their case is broader. But if a person leaves that off, by way of discipline, by way of advice, and by way of disapproval, perhaps he will respond, perhaps he will leave what Allah has forbidden for him; then that is good, especially if leaving it does not result in the loss of a great benefit or the occurrence of a major harm. As for if his presence at this doubtful food includes a benefit and a call to good, and disapproval of what is wrong, and teaching of what is good, then his presence is more preferable and more beneficial in this matter; because the money is doubtful and mixed. Yes.
The presenter: May Allah reward you.