Does a religious obligation (like expiation or vow) prevent the payment of Zakat?
Chapter on Zakat on Debt and Charity
Al-Mughni
Book of Zakat
Primary text
There are two views regarding whether a debt owed to Allah, such as expiation (kaffarah) or a vow (nadhr), prevents the payment of Zakat. The first view holds that it does prevent Zakat, treating it like a debt owed to a person because it is an obligation that must be settled. This is supported by the saying of the Prophet, may peace be upon him: "The debt of Allah is more worthy of being paid."
Supporting text
The second view maintains that it does not prevent Zakat because Zakat is considered more emphasized due to its attachment to the physical asset (al-'ayn), placing it similar to the blood-money (arsh) for injury. This view distinguishes it from a human debt due to its greater emphasis and the direct claim associated with it.