What is the ruling on a conditional divorce whose condition, after its potential occurrence, neither spouse can recall?

If a husband makes a divorce conditional on something, the majority of jurists hold that the divorce takes place when the condition is met. Some scholars, however, are of the view that this constitutes an oath (yamin) for which expiation (kaffarah) is required if the intention was to threaten, encourage, or prevent, and this is the preferred fatwa. So, if the husband did not intend divorce but merely intended prevention, he is obligated to offer expiation for an oath as a precautionary measure. If he did intend divorce but then forgot the condition he made it contingent upon, the divorce does not occur because the original state is the continuation of the marriage, and divorce does not take place based on doubt.