Is a Khul' valid if conditional upon divorcing or not divorcing a co-wife?
General Chapter
Al-Mughni
Book of Khul' (Redemption Divorce)
Primary text
The Khul' is valid, and both the condition and the consideration (Bathl) are binding. This is supported because the woman offered consideration in exchange for her divorce and the divorce of her co-wife, which is valid, similar to when one states: 'Divorce me and my co-wife for one thousand.' If the husband does not fulfill his condition, the wife owes him the lesser amount of what was specified or the one thousand stipulated. Alternatively, it is held that the husband is not entitled to any of the consideration because she only offered it on a condition that was not met, meaning he does not deserve it, just as if he divorced her without consideration.
Supporting text
Al-Shafi'i holds that the condition and the consideration are void, and the matter reverts to the dowry equivalent (Mahr al-Mithl) because the condition acts as a loan in the divorce, and part of the consideration is in exchange for the void condition, rendering the remainder of the consideration indeterminable. Abu Hanifa holds that the condition is void, but the consideration is valid because the contract stands on its own merit regarding the consideration.