Is it permissible to divide the father's money among his children during his lifetime, without the father's knowledge of the amount or his awareness of the division, knowing that the mother manages and spends from the money, and that the Zakat on the money and gold has not been paid? Is Zakat due before or after the division, and is it permissible for one of the children to voluntarily relinquish their share to their siblings?

If the father's wealth reaches the nisab (threshold) and a full lunar year (hawl) passes on it, zakat becomes obligatory on it at a rate of 2.5% for each year that has passed. It is not permissible for the mother or the children to dispose of the father's money without his permission as long as he is of sound mind. If the father is not of sound mind due to senility or similar conditions, then he is placed under guardianship, and the ruler or whomever he appoints manages his wealth. If the father is of sound mind and wishes to divide his wealth among his children, he must be just in his giving, and the mature, sane son may waive his share.