Spending in charity from the money of a deceased
1- My grandson is seven years old. His father who is deceased has a sum of 10, 000 EGP deposited in the Post Office. I would like to know the manner of giving zakat on this sum and its nisab. Is zakat to be paid on the original sum only or on the original sum as well as on its interest?
2- Is it permissible to donate a sum from the money of the deceased as an ongoing charity to benefit his soul without harming his son's interests?
1- The nisab (minimum sum upon which zakat is due) for zakat on wealth is the equivalent of 85 grams of 21 carat gold. Zakat is 2.5%of the original sum. The same percentage is due on the interest if it has been possessed for one year. If not, then no zakat is due on the interest.
2- After death, a deceased does not own any money except for the expenses he needs for the funeral and burial, any bequests that are to be deducted from the money he leaves behind, and the money needed to settle his debts. Anything beyond this belongs to his heirs.
It is impermissible to give an ongoing charity from the estate of the deceased because the heirs include a minor who is not yet legally accountable and it is impermissible to dispose of his property except if it were in his sole interest—giving out in charity for the sake of his father is not. However, each of the heirs—you or any other—may give out an ongoing charity for the benefit of the soul of the deceased, either collectively or individually, since you are legally accountable and will give it out of your own free will.
Allah Almighty knows best.