If the birthday food is Halal and someone has just completed her Iddah can we eat the food that she gave as a form of celebrating it?
All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
Celebrating birthdays is a rite introduced by the enemies of Islam into Islamic community. It is unlawful to celebrate it or make parties for it.
As for the food distributed for this occasion, it is not forbidden in itself, and there is no harm to eat it. But it is unlawful to prepare it intending to celebrate such innovation.
For more benefit on the ruling on celebrating birthdays, please refer to Fataawa 81725, 2130, 13538, 106623, and 131733.
Allah knows best.
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