to fast it, for this fast is not a deliberate singling-out of Friday itself; rather, it is a fast of the day that has happened to coincide with Friday. Thus, if Friday falls on the Day of ʿArafah, fast it without hesitation even if you had not fasted the day before. And if it coincides with the Day of ʿĀshūrāʾ, fast it without hesitation as well. Yet with ʿĀshūrāʾ we are instructed to differ from the Jews, so we should fast a day before it or a day after it. For this reason another hadith says, “except that he fast a day before it or a day after it,” or, “unless it is part of a fast the person is already keeping.”

In the hadith of Juwayriyyah bint al-Ḥārith—may Allah be pleased with her, Mother of the Believers—the Prophet ﷺ said to her while she was fasting on a Friday, “Do you intend to fast tomorrow?” She said, “No.” He asked, “Did you fast yesterday?” She replied, “No.” He then said, “Break your fast.” This proves that if one fasts a day before Friday or a day after it, there is no objection.

His question, “Do you intend to fast tomorrow?” also shows the permissibility of fasting on Saturday as a voluntary act, with no objection or dislike, when it is joined to Friday. A hadith has indeed been reported in which the Prophet ﷺ said, “Do not fast on Saturday except in what has been made obligatory upon you—even if one of you must chew the skin of a grape.” The scholars, however, have differed about this narration. Some have deemed it weak and unsuitable for practice; among them was our teacher, the hadith scholar ʿAbd al-ʿAzīz ibn Bāz, who said, “This hadith that prohibits fasting on Saturday is weak and anomalous; it is not acted upon.” Others maintained that it is abrogated, while others said that—