Does a divorce take effect if a mentally ill man swears to divorce his wife should she fail to do something nearly impossible, and she does not do it, knowing that he did not intend the divorce and was aware of what he was saying?

Scholars differed on the ruling concerning the suspension of divorce on an impossible condition. Some opined that the divorce takes effect immediately, because he appended the divorce with something that negates its entirety and prevents its immediate occurrence. Others held that it does not take effect, because he suspended the divorce on a condition that does not exist, and because what is intended to be deferred is suspended on the impossible, as was said: "When the crow turns gray, I will come to my family... and tar becomes like fresh milk."

It was also said: If he suspends it on what is rationally impossible, it takes effect immediately. But if he suspends it on what is habitually impossible (like flying or ascending to the sky), it does not take effect, because it has an existence, and its like has occurred in the miracles of prophets and the wonders of saints.

However, if it is suspended on a condition that is possible to occur, then it takes effect upon the fulfillment of the condition according to the majority of scholars, with the exception of Ibn Taymiyyah, who holds that it does not take effect if the husband intended by the suspension to urge or prevent, and he must offer an expiation for an oath.

It is advisable to consult the competent authorities to clarify the true meaning of the uttered words and to seek further details.