What are the effects of the delegated person divorcing the wife?
Chapter on Explicit Divorce and Others
Al-Mughni
Book of Divorce
Primary text
Once the authority is established, the delegate may effect divorce unless the husband revokes the delegation or has intercourse with the wife. The delegate can issue one or three divorces, just as the wife could. The authority can only be given to someone capable of being an agent, namely a sane adult. If the husband delegates this authority to a child or an insane person, any resulting divorce is invalid.
Supporting text
The companions of the 'Ahl al-Ra'y (supporters of opinion/judgment) hold that it is valid even if delegated to them. The sound view is that they are not people capable of legal transactions, so their agency is invalid, similar to authorizing them to free a slave.