Can a husband prevent his wife from performing obligatory Hajj or 'Umrah after she has entered the state of Ihram?
Chapter on Ransom (Fidyah) and Penalty for Hunting
Al-Mughni
Book of Hajj
Primary text
The husband is not permitted to prevent his wife from proceeding with obligatory Hajj (Hajjat al-Islam) or a vowed Hajj or 'Umrah, nor force her to exit the state of Ihram, according to the majority of scholars, including Ahmad, Al-Nakha'i, Ishaq, the companions of Al-Ra'y, and Al-Shafi'i in his strongest opinion. This is because obligatory Hajj becomes immediately binding upon commencing it, similar to prayer entered at its earliest time or making up a missed Ramadan fast once begun. If the husband could prevent her this year, he could prevent her every year, leading to the nullification of an Islamic pillar, unlike the waiting period ('iddah) which is temporary.
Supporting text
Al-Shafi'i holds a secondary opinion that the husband may prevent her because, in his view, Hajj is permissible to be delayed (alā al-tarākhi), meaning it is not specifically tied to the current year. However, this view is rejected because obligatory Hajj becomes specific upon commencing it.