What is the ruling on dealing with usurious bank interest by leaving it as is, or by giving it to one's mother, knowing that she is aware of its prohibition? If giving it to the mother is unlawful, what should I do with it?

Money must be withdrawn from a usurious bank, because mere deposit in it is impermissible. Usurious interest should be disposed of by spending it on Muslim welfare or giving it to the poor and needy. It should not be given to the mother unless she is poor. It is not permissible to leave the interest for the bank.