and one of the two opinions of al-Shafi'i. He said in the other: His vow is not valid, because it is not possible to fast after its condition has been met, so it is not valid, just as if he said: 'I have vowed to Allah to fast the day before the day on which he arrives.' Our position is that it is a time in which supererogatory (tatawwu') fasting is valid, so his vow for it is binding, just as if he woke up fasting voluntarily and said: 'I have vowed to Allah to fast this day of mine.' Their statement that 'it is not possible to fast' is incorrect; for he might know the day on which he arrives before his arrival, and thus intend to fast it from the night. Furthermore, it is possible for something to be obligatory upon him even if it is not possible for him, such as a child who reaches puberty during a day of Ramadan, or a woman who becomes pure from menstruation during it. We do not concede the validity of what they have used as an analogy, once its correctness is established. This does not escape five categories: One of them is that he knows of his arrival from the night, so he intends to fast it, and it is a day in which the fasting of a vow is permitted, so his fast is valid and suffices him because he has fulfilled his vow. The second is that he arrives on the day of Fitr or Adha; there is a difference of opinion narrated from Ahmad regarding this issue. According to one narration: He does not fast it, but he makes it up and offers expiation. A group narrated this from Ahmad, and it is the opinion of most of our companions and the school of al-Hakam and Hammad. The second narration is that he makes it up, but there is no expiation upon him. This is the opinion of al-Hasan, al-Awza'i, Abu 'Ubayd, Qatadah, Abu Thawr, and one of the two opinions of al-Shafi'i; because the fast made mandatory by the vow has missed him, so he is obligated to make it up, just as if he had left it out of forgetfulness, and no expiation is required of him because the Sacred Law has prohibited him from fasting, so he is like one who is coerced. From Ahmad, there is a third narration: If he fasts it, his fast is valid. This is the school of Abu Hanifah, because he fulfilled what he vowed, so it resembles the case where one vows an act of disobedience and then performs it. It is also deduced that he should offer expiation without making it up, because he hit upon a day in which fasting is forbidden, so its consequence is expiation, just as if a woman vowed to fast the day of her menstruation. It is also deduced that nothing is required of him, neither expiation nor making it up, based on the one who vows an act of disobedience. This is the opinion of Malik and al-Shafi'i in one of his two opinions, based on the vow of disobedience. The argument for the position of al-Khiraqi is that the vow becomes binding because he made a vow for which fulfillment is generally possible, so it was binding, just as if he hit upon a day other than the day of Eid. It is not permissible for him to fast on the day of Eid because the Sacred Law has prohibited fasting on it, so it resembles the time of menstruation, and he is obligated to make it up because it is a binding vow, and the fasting has missed him due to an excuse, and he is obligated to offer expiation because of its loss, just as if