Does linking the oath of abstinence to an impossible condition constitute Ilaa'?
General Chapter
Al-Mughni
Book of the Oath of Abstention (Ila')
Primary text
If the Ilaa' is conditioned upon an impossible event, such as ascending to heaven or turning stone into gold, it constitutes Ilaa' because the underlying meaning is perpetual abstinence. This is analogous to the verse stating that disbelievers will not enter Paradise until the camel passes through the eye of a needle, meaning they will never enter Paradise (Quran 7:40). If the condition is something naturally impossible, like conceiving without intercourse, it is considered Ilaa', as supported by the reasoning of Maryam's question to the angel: {How can I have a boy when no man has touched me and I have not been unchaste?} [Quran 19:20]. The inability to conceive without penetration is an established impossibility based on custom and religious precedent.
Supporting text
Some scholars, including Al-Qadi, Abu Al-Khuttab, and the companions of Al-Shafi'i, state that if the condition is that she becomes pregnant, it is not Ilaa' unless the wife is a minor girl unlikely to conceive within four months or is post-menopausal. If she is of childbearing age, it is not Ilaa' because conception is possible. However, this is countered by the argument that conception without intercourse is an impossibility by custom, making the oath equivalent to swearing to do the impossible (like ascending to heaven).