Is the waiting period ('Iddah') calculated based on the 'istibra' before the oath or the menstruation cycle within which the oath was sworn?
Chapter on Explicit Divorce and Others
Al-Mughni
Book of Divorce
Primary text
There are two views. The sounder view is that the waiting period is calculated based on the 'istibra' because it achieves what the 'istibra' after the oath achieves.
Supporting text
The second view is that it is not calculated because 'istibra' does not precede its cause, and it is not counted in the 'istibra' of a female slave.