What is the ruling on fasting on the days of Saturday and Sunday?

Question : What is the ruling on fasting on the days of Saturday and Sunday given the prohibition against them? And what is the ruling for one who fasts one day and breaks the fast the next, and his fasting happens to coincide with these two days? Please inform us.

Answer : Regarding fasting on Saturday, some scholars held that it is recommended (mustahabb), stating that because it is the festival of the disbelievers, one should differ from them. Similarly, regarding Sunday, some scholars held that fasting on it is recommended to differ from those who take it as a festival, a day of joy and celebration. And some scholars held that it is disliked (makruh) because fasting in it is a form of honoring this day, which aligns with the disbelievers in their honoring of it. The correct view is that it is neither prescribed (sunnah) nor disliked, and that fasting on them is permissible. Fasting on Saturday is permissible, but it is disliked to fast on it alone if the hadith is authentic, meaning the hadith prohibiting fasting on Saturday and the hadith containing the prohibition of fasting . This hadith is abrogated according to most scholars, and some said it is anomalous (shadhdh) because it contradicts what is established in the two Sahihs that the Prophet (peace and blessings be upon him) said to one of his wives, finding her fasting on Friday: "Did you fast yesterday?" She said, "No." He said, "Will you fast tomorrow?" She said, "No." He said, "Then fast." This indicates that fasting on Saturday is not disliked. The correct statement is that if the hadith is authentic, the only thing disliked is fasting on it alone. As for if it is combined with Friday, or if it coincides with a day on which fasting is prescribed, such as if it coincides with the Day of 'Arafah, then it is fasted alone, because when a person fasts it and it is the Day of 'Arafah, he does not fast it because it is Saturday, but he fasts it because it is the Day of 'Arafah. Similarly, one who fasts one day and breaks the fast the next, if Saturday coincides with his fasting day, there is no harm.