And among the days on which fasting is recommended is fasting on the Day of 'Arafah and the tenth day of the month of Muharram, based on the hadith of Abu Qatadah (may Allah be pleased with him)

The Shaykh : And among the days on which fasting is recommended is fasting on the Day of 'Arafah and the tenth day of the month of Muharram, based on the hadith of Abu Qatadah (may Allah be pleased with him): : The past year is the one that has ended, because the Day of 'Arafah is in the last month of the year, and the coming year is the one that follows, so it expiates two years.
: So it is less in reward than fasting on the Day of 'Arafah, and yet one should fast Tasu'a along with Ashura, because the Prophet (peace and blessings be upon him and his family) said: meaning along with the tenth, and because he ordered that a day before it or a day after it be fasted, in order to differ from the Jews, because the day of Ashura, meaning the tenth of Muharram, is the day on which Allah saved Musa and his people and drowned Fir'awn and his people, so the Jews used to fast it in gratitude to Allah (Mighty and Majestic) for this great blessing: that Allah saved His soldiers and defeated the soldiers of Satan, saving Musa and his people and drowning Fir'awn and his people, so it is a great blessing, and for this reason: : Why? Because the Prophet (peace and blessings be upon him) and those with him are the most deserving of people regarding the previous prophets, : meaning Muhammad (peace and blessings be upon him) : So the Messenger of Allah (peace and blessings be upon him) is more deserving of Musa than the Jews, because the Jews disbelieved in him, just as they disbelieved in 'Isa and disbelieved in Muhammad, : except that he ordered them to differ from the Jews who do not fast except on the tenth, by fasting the ninth, or the tenth and the eleventh, or all three, and for this reason some scholars, such as Ibn al-Qayyim and others, mentioned that fasting Ashura has three categories: fasting Ashura and the ninth, and this is the best of the types.
Fasting Ashura and the eleventh, and this is less than the first.
Fasting Ashura alone, and some scholars disliked it because the Prophet (peace and blessings be upon him) ordered to differ from the Jews, while some scholars permitted it.