Is it permissible to eat at the homes of sons who inherited from their father and deprived their sisters of their inheritance, considering their wealth to be unlawful, or is that considered upholding the ties of kinship?

Depriving females of inheritance is a pre-Islamic custom that Islam fought against. Allah Almighty Himself undertook the division of inheritance and gave every rightful owner their due, in accordance with His saying: "For men is a share of what the parents and close relatives leave, and for women is a share of what the parents and close relatives leave, be it little or much - an obligatory share." Therefore, brothers must give their sisters their share unless the sisters willingly waive it. As for eating food from someone who has deprived his sisters of inheritance, it is permissible if he has other lawful wealth and the food is not from the very essence of the unlawful, while it is obligatory to advise him to render rights to their owners and to enjoin good and forbid evil upon him.