What is the ruling on eating food cooked in the month of Muharram with the intention of offering it as a gift and a reward to Al-Hussein ibn Ali, may Allah be pleased with them both? And if it is not permissible to eat it, must it be discarded?

Holding parties and gatherings to mark the passing of a year since the death of a deceased person, such as Al-Husayn (may Allah be pleased with him) or others, is an innovation (bid'ah) and a newly invented matter that a Muslim must avoid and advise those who practice it against. It is permissible to accept gifts from them on this occasion if there is a benefit in doing so, analogous to the permissibility of accepting gifts from disbelievers on their holidays. However, if the benefit lies in returning the gift to deter people from innovations, then it should be returned gently, explaining the reason: that it is associated with an innovative occasion, and out of a desire to eliminate this innovation.