Thus, if a man says, “By Allah, I will not speak to so-and-so,” then speaks to him forgetfully, we say to him: Nothing is due from you. But does his oath remain in force or is it dissolved? It remains in force, though he has not broken it; that is, we do not require him to offer expiation.
The same applies if he does so out of ignorance. If he says, “By Allah, I will not wear this garment,” then wears a garment thinking it to be another one, only to discover that it was the garment concerning which he had sworn, he has not broken his oath. However, once he realizes this, he must take it off, and his oath remains in force.
Likewise, if he does it under compulsion—for example, if he is forced to do the thing concerning which he swore and consequently does it—he has not broken his oath, but the oath remains in force.
The same is true if he does it while asleep. If he says, “By Allah, I will not wear a headcloth today,” then falls asleep while a headcloth is beside him and puts it on, nothing is due from him, because he is asleep. This is why, if someone in the state of ihram covers his head while asleep, nothing is due from him. But once he wakes up, he must remove it; otherwise, he breaks his oath.
His statement, “He breaks his oath only in matters of divorce and manumission,” means that in matters other than these two, he does not break his oath. An example involving divorce is where he says, “If I wear this garment, then my wife is divorced,” and then forgets and wears it: his wife is divorced. Likewise, if he says, “If I wear this garment, then my wife is divorced,” and wears it unaware that it is the garment upon which he made the divorce conditional, his wife is divorced. This is because divorce is a human right, and human rights do not admit the excuse of ignorance or forgetfulness. That is the reason.
The same applies to manumission. If he says, “If I wear this garment, then my slave is free,” and then wears it forgetfully or unknowingly, the slave is manumitted. The underlying reason is what has preceded: it is a human right, for which ignorance and forgetfulness are not excused. The author should also have mentioned a third case: compulsion.