If one is obligated to fast two months for the expiation of Zihar or similar obligations, and concurrently has a vow (Nadr) of fasting, which obligation takes precedence?
General Chapter
Al-Mughni
Book of Vows
Primary text
If one intends the vow at the beginning of the required expiation fast, the continuity required for the expiation is broken, thus rendering the expiation invalid. Therefore, the obligation is to complete the expiation first, and then fulfill the vow. This differs from Ramadan days, which did not enter the vow due to impossibility; here, the expiation days could have been fulfilled for the vow, but intending the vow breaks the required continuity for expiation, meaning the fast fulfills the vow but not the expiation obligation.
Supporting text
This ruling applies whether the vow preceded the obligation of expiation or followed it, because the days of Ramadan cannot validly be counted for the vow, whereas the days of expiation *could* be counted for the vow, thus breaking the continuity required for expiation.