What is the ruling on benefiting from bank or post office interest, and is it permissible to donate it, and is it permissible to give it to one's parents?

The usurious gains must be disposed of with the intention of getting rid of them, not as charity. This money should be spent on the welfare of Muslims, the poor, and the needy. It is permissible to give it to a poor relative whose maintenance is not obligatory upon oneself, but it is not permissible to give unlawful money to those whose maintenance is obligatory, such as parents, unless the son is poor. It is forbidden to deposit money in usurious institutions except out of necessity.