The ruling on eating from the wealth of a person whose lawful and unlawful earnings are mixed

She says about herself: My brother’s lawful and unlawful wealth is mixed, and out of scrupulousness, we do not eat from his food unless we are in his house. The mother wants us to eat and gets angry if we do not. Which is better: this scrupulousness or obeying the mother?
Answer: There is no harm in eating. Praise be to Allah. The Prophet (peace and blessings be upon him) ate from the food of the Jews, and their food contained riba (usury or interest) and things that are not permissible. As long as you do not know which is which, and it is mixed such that one cannot distinguish this from that, the original ruling is permissibility and safety. So you may eat from his wealth, and advise him to beware of the forbidden and to give charity from his wealth equal to the amount of the forbidden, so that his conscience is cleared.
The presenter: May Allah reward you with good and do you good.