عَنْ هُنَيْدَةَ بْنِ خَالِدٍ عَنِ امْرَأَتِهِ عَنْ بَعْضِ أَزْوَاجِ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ قَالَتْ: كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ يَصُومُ تِسْعَ ذِي الْحِجَّةِ وَيَوْمَ عَاشُورَاءَ، وَثَلَاثَةَ أَيَّامٍ مِنْ كُلِّ شَهْرٍ أَوَّلَ اثْنَيْنِ مِنَ الشَّهْرِ وَخَمِيسَيْنِ
A wife of the Messenger of Allah (may Allah be pleased with her) narrates that the Messenger of Allah (peace and blessings be upon him) used to fast on the 9th of Dhul-Hijjah, the Day of Ashura, and three days of every month. (The details of these three days are:) the first Monday of every month and two Thursdays.