If a person vows charity using a portion of an asset upon which Zakat is due, and the vowed portion is equal to or greater than the Zakat amount, how is the obligation settled?
Chapter on Zakat on Debt and Charity
Al-Mughni
Book of Zakat
Primary text
Under one possibility, the vowed portion is given out, and the intent is made that the Zakat amount within that payment fulfills the Zakat obligation.
Supporting text
According to Ibn 'Aqil's view, it is possible that Zakat remains obligatory because the vow was tied to the portion only after the cause for Zakat and fulfillment of its conditions had already occurred; thus, the obligation of Zakat is not prevented since the asset is sufficient for both obligations.