What is the ruling on someone who vowed to fast three days if he committed a certain sin, and linked this to an expiation for an oath (kaffarat yameen) that recurs with the recurrence of the sin, then he fell into several similar sins? And is it permissible to be released from this vow, or does it remain binding upon him? And what if these sins recur many times?

A vow intended to prevent oneself from a specific action is called a vow of obstinacy and anger (نذر اللجاج والغضب). The person who makes it has the choice between fulfilling it or offering an expiation for breaking an oath (كفارة اليمين). If the breaking of the vow (حنث) occurs repeatedly for the same action without expiating the first instance, then the expiations overlap, and a single expiation suffices. However, if the vow is repeated every time the action occurs, then its effect, whether the vowed fasting or the expiation for breaking an oath, also recurs.