The ruling on sitting with one who deals in riba (usury or interest) and eating from his food

Question:
May Allah reward you. The questioner is from Syria. He says: If a person deals in riba, is it permissible for us to mix with him and eat the food he serves us?

Answer:
You should prevent him from it, remind him of Allah (Mighty and Majestic), and bring the verses and hadiths that prohibit riba, as well as the words of the scholars, so that perhaps he will repent to Allah (Mighty and Majestic). As for eating his food, if he has nothing but riba, then it is not permissible to eat from his food because it is forbidden. However, if he has mixed wealth from what is lawful and what is forbidden, there is no harm in eating from his food, because it is not established that it is from the riba.