What is the requirement concerning actions that break the fast prior to forming the daytime intention for a voluntary fast?
General Chapter
Al-Mughni
Book of Fasting
Primary text
It is a condition for the validity of the fast that nothing that breaks the fast, such as taste or consuming anything, occurs before the intention is made. If such an action occurs, the fast is invalid, without any known disagreement.
Supporting text
The argument that the fast is indivisible is considered the core point of contention. It is argued that the validity of fasting a part of the day requires that no invalidating acts occur during any part of the day, as indicated by the Prophet's instruction in the Ashura hadith to "fast the remainder of his day." This is distinct from forgetting an intention made previously, where the ruling remains established.