How is the Zakat on the money of a father-in-law suffering from Alzheimer's to be paid, given that his son was entrusted with distributing his monthly profits to his siblings since 2010, knowing that this money is essential for their livelihood?

If the money is in an interest-based bank, it is not permissible to benefit from its interest. The principal must be withdrawn, and the interest disposed of by spending it on Muslim welfare or donating it to the poor, with the poor person being permitted to benefit from it. The principal must be invested in Islamic financial institutions or permissible mudarabah (profit-sharing) ventures. If the owner of the money loses their sanity, they are interdicted, and a guardian is appointed for them by the ruler to look after their interests. The guardian must develop the money by trading with it. The profits belong to the owner of the money and are to be spent on them. Any surplus is added to the principal. If one of the owner's children is poor and unable to earn a living, their maintenance is obligatory upon the father. Zakat is obligatory on the principal and its profit every Hijri year, even on the money of a minor or an insane person. The previous power of attorney becomes void upon the loss of sanity and the interdiction of the owner of the money.