Can a master prevent his slave from fasting to fulfill an expiation oath?
General Chapter
Al-Mughni
Book of Expiations
Primary text
The master is forbidden from preventing his slave from fasting as expiation, whether the oath was sworn and broken with or without the master's permission, and whether the fast causes harm to the slave or not. The justification is that this fast is an obligation due to the right of Allah (Exalted is He), and thus the master cannot prevent it, similar to the obligatory fast of Ramadan and its makeup. This differs from Hajj, where the master can permit its dissolution due to the great harm involved, absence, and loss of service.
Supporting text
Al-Shafi'i held that if the slave broke the oath without permission and the fast causes the master harm, the master may prevent it because he did not permit what incurs harm upon him. This is analogous to the master preventing the slave from entering Ihram for Hajj without permission.