"One of the wives of the Prophet said: "The Prophet used to fast on the day of 'Ashura, nine days of Dhul-Hijjah and three days each month: The first Monday of the month, and two Thursday."
حَدَّثَتْنِي بَعْضُ نِسَاءِ النَّبِيِّ ﷺ أَنَّ النَّبِيَّ ﷺ كَانَ يَصُومُ يَوْمَ عَاشُورَاءَ وَتِسْعًا مِنْ ذِي الْحِجَّةِ وَثَلاَثَةَ أَيَّامٍ مِنَ الشَّهْرِ أَوَّلَ اثْنَيْنِ مِنَ الشَّهْرِ وَخَمِيسَيْنِ