Is it permissible for a man who has four wives to marry a fifth woman after divorcing one of them, but before the divorced wife's waiting period (iddah) ends, and is it permissible for the divorced woman to return to her husband after her waiting period ends?

Khul' is an irrevocable divorce (طلاق بائن), and the husband cannot take back his wife who sought khul' except with a new marriage contract. Scholars differed on the permissibility of a man marrying another woman in place of a fourth wife whom he divorced with an irrevocable divorce while she is still in her waiting period (iddah). Malik and Shafi'i held it permissible, while Abu Hanifa and Ahmad held it impermissible until her iddah expires. If the marriage takes place, it is valid. Reconciling with the wife who sought khul' after her iddah expires is permissible with a new contract.