Does menstruation interrupt the sequence of fasting for an oath's expiation, and must one repeat fasting the first day if menstruation begins on the following day, or can one complete the fasting after purification?

Fasting as expiation for an oath is only permissible after being unable to feed or clothe ten poor people. Furthermore, consecutive fasting for this expiation is preferable. Menstruation does not break the continuity of an obligatory fast, so the fast of the first day, which occurred before menstruation, is valid. Then you should fast for two days after the cessation of menstruation, because a woman has no control over breaking the fast due to menstruation.