Is it permissible to sell the husband's gold and donate its price on behalf of the deceased father, without the husband's knowledge, to contribute the money to building a mosque as an ongoing charity (Sadaqah Jariyah), and will the reward reach the deceased?

If the husband gave his wife gold for his adornment, she is not permitted to dispose of it without his permission, out of consideration for his intention. Jurists have stipulated the obligation to consider the intention of the donor. However, if she owns the gold for a purpose other than this, she may dispose of it as she wishes. She may sell it and donate from it as much as she desires, and the reward will reach her father.