Arbaʿīn, signifies the fortieth day after the martyrdom of Imam al-Ḥusayn which is commemorated annually by Imāmī Shiʿis. According to an early belief, it was on this day that the severed head of al-Ḥusayn b. ʿAlī was reunited with his body at Karbalāʾ.

The significance of the fortieth day after the death of a believer is evident among Muslims since the earliest period, and it is manifested in two ways: on the one hand, it has a metaphysical meaning, which suggests a kind of maturation of the deceased soul; on the other, it is a period d…