Q 1: We know that it is not permissible to celebrate what is called Neyruz (Iranian new year holiday), as it is one of the feasts of the Magi. The question is: Is it permissible to eat the foods served at these feasts several days later?
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It is not permissible for a Muslim to observe any of the rituals of disbelief and Shirk (associating others with Allah in His Divinity or worship), including the religious occasions such as festivals and others.
It is not permissible to eat the food served at feasts and celebrations associated with Shirk and Bid`ah (innovation in Islam). This is a sort of participation with and approval for them as they are. A Muslim should be very keen to maintain his Islamic practices unblemished.May Allah grant us Success! May peace and blessings be upon our Prophet Muhammad, his family, and Companions.