What is the ruling on fasting the Day of Ashura if it falls on a Saturday?

The Shaykh : As for the one who fasts the ninth day intending not to fast the sixth, in obedience to his command (peace and blessings be upon him), his action is better than that of the one who fasts, because the Messenger (peace and blessings be upon him) used to say: I do not know if this is the answer?
Al-Halabi : Our Shaykh, the issue that was raised is that some of our brothers discussed the matter and mentioned a word, which is what led to this discussion being raised, namely that the ninth day was prescribed only for the sake of the tenth day, so if the tenth day is not fasted, the ninth day follows it; is this statement on the table for discussion?

The Shaykh : This has already been answered.
Al-Halabi : Yes, it has become one of the statements of some scholars that you indicated, whether it is correct or incorrect.

The Shaykh : And with that, I add to it.
Al-Halabi : May Allah reward you with good.

The Shaykh : Now, based on what has preceded, I add that the Jews, in any case, do not fast the ninth day; so if we assume a person, for some reason, does not want to fast Ashura, is it better to fast the ninth day to differ from the Jews? Or should he not fast the ninth day nor the tenth day? It is better to fast the ninth day because it involves differing from the Jews.

The questioner : The Prophet (peace and blessings be upon him and his family) said: .

The Shaykh This text suggests that it is an alternative; but it is not the alternative, rather it is the preferred one. Yes, this is exactly similar; once I mentioned to you a story about a dream seen by one of the Companions. He was walking in Madinah when a man said to him: What did the Messenger of Allah (peace and blessings be upon him and his family) teach you to say from the remembrances after prayer? He said: Thirty-three times Subhan Allah, and so on, which is well known. The man in the dream said to him: Make it twenty-five of each, meaning Subhan Allah, Alhamdulillah, La ilaha illa Allah, and Allahu Akbar, twenty-five times each. When morning came and he related the dream to the Messenger (peace and blessings be upon him), he said: Then do so. This is undoubtedly a new legislation, but is it an abrogation of the old? No, this is a new preferred legislation. So if a person continues to practice the old, it is an old legislation that has not been abrogated. This is approximately like that.
Al-Halabi : Yes, correct. May Allah reward you with good.

The Shaykh : And beware of that.