What is the ruling on fasting Saturday if Ashura (Sunday) falls on it?

Fasting on Ashura is a Sunnah that expiates the sins of the past year. It is also a Sunnah to fast the day before it, which is the ninth, even if it falls on a Saturday. This is because the dislikedness of singling out Saturday for fasting is removed by fasting a day before or after it, or by it coinciding with a habitual fast. As for the Hadith prohibiting fasting on Saturday, there is disagreement concerning it. Some scholars have deemed it weak or abrogated, while others consider it an authentic and firm text, with the dislikedness applying to singling out Saturday for fasting. There is no dislikedness if it is fasted with another day or if it coincides with a habitual fast.