Does a divorce take effect if the husband says to his brother, "Divorce me if you do such and such," and then his brother does that on the same day? And what is the expiation for this oath?

Scholars have differed on the occurrence of divorce if the husband intended merely to threaten with it, to prevent his brother from doing something, and did not intend to suspend the divorce. The majority of them hold that it occurs, while some have maintained that it does not occur and that he is liable for an expiation for breaking an oath (kaffarat yamin (definition)). The more cautious view is that of the majority. However, if he intended to suspend the divorce, then it occurs among all scholars the moment the condition upon which it was suspended takes place.