Is the purpose of the waiting period (Iddah) the ascertainment of the woman's freedom from pregnancy (Istibra')?
General Chapter
Al-Mughni
Book of Waiting Periods ('Iddah)
Primary text
The waiting period serves as a means of ascertaining freedom from pregnancy (Istibra'), similar to the Istibra' required for a female slave. This ascertainment is achieved through menstruation because it demonstrates the absence of pregnancy, as pregnancy and menstruation cannot coexist. Therefore, the ruling should adhere to the indicator that signifies freedom from pregnancy, which is menstruation.
Supporting text
A counterargument suggests that the Istibra' for a female slave is achieved through the period of purity preceding the menstruation, not the menstruation itself. However, this is refuted by the Prophet's statement, 'A pregnant woman is not to be mated until she delivers, nor one whose womb is clear until she is cleared by one menstrual period,' indicating that clearance is achieved by the menstrual flow itself, which confirms the womb's emptiness.