As for the Day of Doubt—that is, the day about which one is uncertain whether it is the last of Shaʿbān or the first of Ramaḍān—the majority of scholars forbid fasting it with the intention that it belongs to Ramaḍān. Their ruling rests on the outward purport of the prophetic reports that make the validity of the fast dependent upon sighting the new moon or completing the thirty-day count, save for what we have already mentioned of Ibn ʿUmar’s view.

They disagreed, however, about voluntarily fasting that day. Some considered it disliked, taking at face value the ḥadīth of ʿAmmār:

“Whoever fasts the Day of Doubt has disobeyed Abū al-Qāsim.”

Others allowed it, citing the reports that the Prophet, peace and blessings be upon him, fasted the whole of Shaʿbān, and that he said:

“Do not precede Ramaḍān by fasting a day or two, unless it coincides with a fast one of you habitually observes; in that case let him fast.”

Al-Layth ibn Saʿd said: If a person fasts that day thinking it is Ramaḍān and later reliable confirmation reaches him that it was indeed Ramaḍān, the fast is valid. This, he argued, shows that the intention may be made after dawn when one shifts from a voluntary to an obligatory fast.

Regarding Saturday: their disagreement stems from whether the following report is sound, that the Prophet, peace and blessings be upon him, said,

“Do not fast on Saturday except for what has been made obligatory upon you,”

recorded by Abū Dāwūd. Some maintained that this ḥadīth was abrogated by the report of Juwayriyyah bint al-Ḥārith, who related that the Prophet, peace and blessings be upon him, entered upon her on a Friday while she was fasting and said, “Did you fast yesterday?” She replied, “No.” He asked, “Do you intend to fast tomorrow?” She said, “No.” He then said, “Then break your fast.”

As for perpetual fasting—fasting every day of the year—the prohibition of it is established. Yet Mālik saw no harm in it, perhaps interpreting the prohibition as a precaution against weakness and illness.

With regard to fasting during the latter half of Shaʿbān, some scholars deemed it disliked while others permitted it. Those who considered it disliked