What is the legal status of a Muhallil marriage (marriage intended to permit a previously divorced woman to remarry her first husband)?
Chapter on Marriage of Polytheists
Al-Mughni
Book of Marriage
Primary text
The marriage of a Muhallil is invalid (fasid). All legal rulings pertaining to invalid contracts apply to it. It does not establish Isan (lawful permanence/chastity) for the woman, nor does it make her lawful again for the first husband, just as is the case with all other invalid contracts.
Supporting text
The designation of the Prophet (peace be upon him) calling the second husband a Muhallil does not imply that the desired legal consequence (Hal, i.e., making the first marriage lawful again) is achieved. This designation is based on the intent to achieve something that is not legally established in that context, similar to the verse where one who permits the forbidden is treated as having committed the forbidden act. If the marriage truly resulted in lawful permission, the parties involved would not be condemned.