What are the reasons for the annulment of a marriage contract, who carries it out, and what is the difference between it and khulʿ (divorce at the wife's instance) and ṭalāq (unilateral divorce by the husband), especially concerning the mahr (dowry), ʿiddah (waiting period), and child custody?

Dissolution (faskh) has multiple causes, including: the presence of a repulsive defect in one of the spouses, the husband's insolvency regarding maintenance, the marriage being null and void from its inception, one spouse refusing to embrace Islam after the other has done so, the option of puberty or recovery from insanity according to the Hanafis, and the apostasy of one or both spouses.

Dissolution (faskh) is dependent on the judge's ruling in matters of disagreement, whereas it is not dependent on a ruling in matters of agreement.

Custody (hadhanah) is established for the mother unless there is an impediment.

The wife is not entitled to the dower (mahr) in the case of dissolution before consummation, but she is entitled to it after consummation, unless the dissolution was due to a defect in her that she concealed.

The waiting period (iddah) in the case of dissolution is by istibra' (clearing of the womb), and there is disagreement regarding its duration, whereas the waiting period for khul' (divorce at the wife's instance) is by the istibra' of one menstrual cycle.