What is the ruling if the wife's agent concludes Khul' using less than the specified compensation?
General Chapter
Al-Mughni
Book of Khul' (Redemption Divorce)
Primary text
When the wife's agent is authorized for a specified compensation, and concludes the Khul' for that amount or less, the Khul' is valid, and that amount is obligatory upon her, as she has benefited from a greater concession. If the agent concludes it for more than specified, the Khul' is valid, but the excess is not obligatory upon her because she did not authorize it. The excess becomes obligatory upon the agent, as he assumed liability to the husband, similar to a manager who purchases a slave belonging to the owner's kin.
Supporting text
Al-Qadi stated that the fair dower (mahr al-mithl) is obligatory upon her, with no liability on her agent, as the agent accepts the contract for another party, not for himself. However, the stronger opinion is that she is not obligated for more than what she offered, as she did not commit to more, nor did she mislead the husband. Nor should the husband receive more than what the agent offered, as he consented to that as a valid, known compensation.