What should a sister do concerning her husband who deals in usury and does not heed advice, and what should her family do, and what is the ruling on eating at his house and on the food, clothing, and sustenance of the sister and children?

Borrowing with usury is one of the gravest sins. The sister should advise her husband and warn him of the consequences of usury, urging him to repent. Regarding benefiting from the husband's wealth, if the money itself is unlawful, such as stolen or usurped property, then it is not permissible to benefit from it. However, if it was acquired through unlawful means, such as prohibited transactions, then scholars have differed on the permissibility of benefiting from it.