Must the heirs pay Zakat on gold for the past 30 years on behalf of their deceased father, knowing that he was unaware of its obligation? And does the amount of Zakat differ now from previous years? And is it permissible to pay it to a brother who is in debt?

First: The nisab (minimum taxable amount) for gold, on which zakat becomes obligatory, is 85 grams of pure gold, 24-karat. As for 21-karat gold, it is calculated by multiplying the number of grams by the karat and dividing by 24. If the result reaches 85 grams or more, zakat (2.5%) becomes obligatory.

Second: If your father owned gold that reached the nisab and he did not pay its zakat, then the accumulated zakat must be paid from his estate before its distribution, because zakat is a debt that takes precedence over inheritance. His ignorance of the nisab absolves him of sin, but it does not absolve him of the obligation to pay zakat.

Third: The amount that must be paid is 2.5% of the gold for each year, noting that the gold decreases each year. Zakat is calculated for each year on the remaining balance after the zakat of the previous year, and the zakat is paid either in gold or its cash equivalent at the current day's price.

Fourth: Zakat is not given to ascendants (parents, grandparents) or descendants (children, grandchildren). However, it is permissible to give zakat to a son who is in debt from his father's zakat to repay his debt, and this is valid during the father's lifetime. After his death, it is more cautious not to give it to him. However, if your brother is in debt, it is permissible to give him from this zakat to repay his debt.