Does a wife have the right to seek annulment (faskh) if she was aware of the husband's impotence (innah) at the time of the contract?
Chapter on the Term for the Impotent and the Castrated who is not amputated
Al-Mughni
Book of Marriage
Primary text
If a wife knows of the husband's impotence at the time of contracting the marriage, such as if he informs her, or if the waiting period is set while she is his wife, leading to dissolution and subsequent remarriage, she is not granted a waiting period for the annulment. This is the opinion of the majority of early scholars, including 'Ata, ath-Thawri, Ibn al-Qasim, and the Ashab ar-Ra'y, as well as the old opinion of Ash-Shafi'i. The justification is that she consented to the defect, entered the contract knowing it, thus forfeiting her right to annulment, similar to knowing he is castrated. If she consented to remaining with him after the period and then divorced and remarried him, she would not have the right to demand annulment, applying the same logic here.
Supporting text
Ash-Shafi'i's new opinion states that a waiting period should be set because impotence may apply to one marriage but not another. This is countered by arguing that impotence is an inherent, seemingly unchangeable physical condition, and since the right to annulment is established after the waiting period, consenting beforehand should void the right, analogous to consenting to other defects.