Does a break in consecutive fasting for expiation due to a valid excuse invalidate the sequence?
General Chapter
Al-Mughni
Book of Expiations
Primary text
If a woman breaks the fast due to menstruation or illness, or a man due to illness, the consecution is not interrupted. This is the position of Abu Thawr and Ishaq, as the break is due to a permissible excuse, similar to menstruation in the expiation for killing.
Supporting text
Abu Hanifah holds that the sequence is broken for both sickness and menstruation because the condition of consecution was not met, and the failure of the condition invalidates the conditioned act. Al-Shafi'i holds that sickness breaks it (in one opinion) but menstruation does not.