Is it permissible to break a voluntary fast?

Question : Breaking a voluntary act, whether it is fasting or something else. I mean, is it permissible or not?

Answer : This is a matter on which the scholars have differed: is it permissible for a person to break a voluntary act once he has started it, or is it not permissible? As for an obligatory act, there is no dispute that it is not permissible to break it. If a person begins an obligatory act, whether it is one of the five pillars or something else, it is not permissible for him to break it, because once he has started it, he is required to complete it. So if he starts making up a fast from Ramadan, it is forbidden for him to invalidate that fast. If he starts a fast for expiation, it is forbidden for him to invalidate that fast. If he starts the midday prayer, for example, it is forbidden for him to read it except for an excuse, but without an excuse it is not permissible.