Is expiation obligatory for one who swore by Allah, "You will never succeed in this," to a person attempting to breach a wall with a water gun? And does expiation multiply if this oath is repeated in the same gathering? And does the same ruling apply to similar situations?

Scholars differed concerning the ruling on swearing an oath about a future matter where the swearer believes himself to be truthful. The majority of scholars hold that it is a binding oath necessitating expiation (kaffarah). However, Ibn Taymiyyah views that there is no breaking of the oath (hant), and the more cautious approach is to offer expiation.

Expiations multiply with the multiplication of oaths. If the oaths are of the same kind, such as repeatedly swearing to do one specific thing, then one expiation is required according to the majority of scholars, while some hold that expiations multiply.

However, if the oaths are of multiple kinds, then an expiation is required for each oath according to the majority of scholars. If one breaks all of them before offering expiation, the view of most scholars is that multiple expiations are obligatory. Some, however, hold that a single expiation suffices.