What is the expiation for multiple oaths regarding abstaining from masturbation, and does the obligatory expiation differ based on the wording of the oath?

If someone swears multiple times concerning the same thing, a single expiation (kaffarah) is due for all the oaths. This applies to someone who is unaware of the consequences of the oath. Another expiation becomes obligatory if they have already atoned for the first oath, then swear again afterward, and break that oath. However, if they intended multiple expiations, then multiple expiations are incumbent upon them. And it is not permissible for them to do what they swore upon if it constitutes an act of disobedience (ma'siyah).