What is the ruling on visiting relatives whose family member works in a usurious bank, and eating their food, drinking their beverages, or accepting their gifts? And is there a way to maintain ties of kinship without falling into the unlawful?

It is not permissible to work in interest-based banks because it constitutes cooperation in sin. The Messenger of Allah, peace and blessings be upon him, "cursed the one who consumes usury, the one who pays it, its scribe, and its two witnesses," and he said: "They are all equal." As for visiting relatives who work there, there is no harm in it, along with advising them to repent. It is preferable to avoid their food, drink, and gifts, following the noble Prophetic tradition: "Indeed, Allah is good and accepts only what is good," unless it is not known that all of their earnings are unlawful, or that the gift or food was purchased with specifically unlawful money. In that case, there is no harm in accepting what they offer.