Is a vow broken if a husband says, 'If you forbid me from benefiting my mother, you are divorced,' and the wife forbids him from giving anything from her wealth to his mother?
Chapter on Explicit Divorce and Others
Al-Mughni
Book of Divorce
Primary text
If a husband states, 'If you forbid me from benefiting my mother, you are divorced,' and the wife tells him, 'Do not give anything of your wealth to her,' the vow is not broken. This is because providing benefit from his wealth to his mother is impermissible, and the benefit itself is unlawful. Consequently, this specific benefit is not covered by the oath.
Supporting text
It is possible that the vow is broken because the term used is general ('benefit'), and the prohibition pertains to general benefit, thus encompassing the forbidden act.