Is it permissible for someone who intended to fast while having a valid excuse (travel, sickness, minority) to break their fast if the excuse is removed mid-day?
General Chapter
Al-Mughni
Book of Fasting
Primary text
If a person intended to fast while traveling, sick, or a minor, and their excuse ceases during the day, it is not permissible for them to break their fast, according to a single narration. If sexual intercourse occurs in this state, the Kaffarah is obligatory upon them.
Supporting text
Some companions of al-Shafi'i held two views specifically regarding the traveler: one view supported that the traveler may break the fast because permission to break the fast was granted at the start of the day, allowing continuation. This is refuted by stating that since the cause for the concession was removed before the person fully availed themselves of the allowance, they lose the right, similar to a ship arriving before one shortens the prayer, or a sick person recovering, or a minor reaching puberty.