Is it permissible for a mother to give bank interest to her married daughter, who has been abandoned by her husband, and for whom he does not provide financially, neither for her nor for her children? And what is the method for disposing of bank interest money? And what is the ruling on a husband who leaves his wife in such a state?

The maintenance of the wife and children is obligatory upon the husband, as Allah Almighty says: "And upon the father is their provision and their clothing according to what is reasonable." Neglecting their sustenance is a grave sin. If the mother spent on her daughter and grandchildren with the intention of a loan, she has the right to demand from the husband what she spent and to take the matter to court. As for usurious (ribawi) gains, it is ill-gotten wealth that must be spent on the general welfare of Muslims, such as the poor. If this daughter and her children are in need, there is no objection to giving them from it, and the principal capital must be withdrawn from usurious banks immediately.