Is it obligatory to dispose of the usurious interest that resulted from money deposited by a father in a bank for his young son, knowing that the son was not aware of its prohibition at the time? And is this interest calculated before or after the age of puberty?

These usurious gains are ill-gotten wealth that must be disposed of by spending them on public welfare aspects for Muslims, such as the poor and the needy, and general Muslim interests. It is not permissible to benefit from any of it except out of dire necessity. The fact that the father was the one who deposited the money is not an excuse for keeping it, for the consideration is his action and his knowledge of the prohibition of usury. The calculation of the interest is from the day it was deposited in the bank until the day it is withdrawn.