What is the ruling on swearing an oath on the Mus'haf that the questioner was not the cause of her ex-husband's imprisonment, and what is the expiation for such an oath?

It is not permissible to swear by Allah falsely, even if it is to obtain a right. Lying may be forbidden even if its intent is to reach a right. However, prevarication (tawriyah) and interpretation (ta'wil) offer a way out of lying to obtain a right, such that the swearer intends by her words something that contradicts their apparent meaning. Lying is permissible in specific situations, such as in war, a man dealing with his wife, reconciling disputes, and repelling injustice. However, when it comes to swearing, the matter differs due to the trivialization of Allah's name. Therefore, prevarication must be used. If a false oath is sworn, there is no expiation for it if the oath concerns a past event. Expiation is only required for an oath concerning a future event.