it falls within that period, is the fast valid? If it does not fall within it, is the fast invalid? And does casting off one’s intention after dawn necessitate breaking the fast even though one has not eaten or drunk? Over all of these points the jurists have disagreed.
Concerning whether intention is a condition for the validity of fasting: this is the position of the majority. Zufar alone dissented, saying that the fast of Ramadan requires no intention unless the person who enters the month is sick or traveling and nevertheless wishes to fast.
The root of their dispute lies in a possible characterization of fasting: is it an act of worship whose rationale is perceptible, or one whose rationale is not perceptible? Whoever considers the rationale imperceptible requires a deliberate intention; whoever regards it as perceptible maintains that the objective is attained by abstaining, even without intention. Yet Zufar’s restricting this view to Ramadan alone is weak, for it appears that when he saw that breaking the fast is impermissible during the days of Ramadan he concluded that any abstention in those days automatically counts as a legally prescribed fast—a peculiarity, in his view, confined to that month.
As for their disagreement over what degree of specification in the intention is sufficient: Mālik held that one must explicitly designate the fast of Ramadan; neither a mere resolve to fast in general nor an intention to observe some other specified fast suffices. Abū Ḥanīfah, however, said that a general resolve to fast is enough, and likewise if one intends a fast other than Ramadan it still suffices—the intention is converted to Ramadan—except in the case of a traveler. If a traveler, during Ramadan, intends to fast something other than Ramadan, it counts as what he intended, because the obligatory fast of Ramadan is not specifically binding on him at that moment. Abū Ḥanīfah’s two companions did not distinguish between resident and traveler, saying: every fast intended during Ramadan is converted to the fast of Ramadan.
The reason for their divergence is whether, in this act of worship, it is sufficient to specify merely the genus of the act or whether the particular act itself must be named. Both patterns are found in the Sharīʿah. For example, in wuḍūʾ it is enough to intend the removal of ritual impurity for whatever act of worship purification is a prerequisite; a separate intention is not required for each act. In prayer, however, one must name the specific prayer—ʿAṣr as ʿAṣr, Ẓuhr as Ẓuhr—according to the well-known view. Fasting, therefore, hovers between these two categories: those who liken it to the first say that a general intention to fast suffices, whereas those who liken it to the second require explicit designation.
They also disagreed about whether, if a person intends some other fast during the days of Ramadan, that intention is converted to Ramadan or not. The cause of this disagreement likewise is that, in their assessment, certain acts of worship can be transformed because the time in which they are undertaken is reserved for the act to which they revert, while most acts cannot be transformed. The one act that all agree does transform is the pilgrimage: if someone upon whom the obligatory Hajj is due begins a voluntary pilgrimage, the voluntary is converted into the obligatory. They did not say this regarding prayer or any other act of worship.