Is an oath suspended upon an external person's will an Ila'?
General Chapter
Al-Mughni
Book of the Oath of Abstention (Ila')
Primary text
If a husband swears, "By Allah, I will not approach you unless your father wills it," or the will of another specific person, he does not become a Muli. This is because he suspended the oath upon an action whose occurrence is not unlikely within the four months, and which is neither forbidden nor harmful, making it similar to saying, "By Allah, I will not approach you unless you enter the house."
Supporting text
The opinion held by Al-Qadi is that the oath is established, and if she wills it, the oath is dissolved; otherwise, it remains binding. However, the prevailing view is that suspending the oath upon an act that can reasonably occur within the four-month period does not constitute Ila'.