حَدَّثَنَا أَبُو كُرَيْبٍ، حَدَّثَنَا أَبُو أُسَامَةَ، عَنِ الْوَلِيدِ، - يَعْنِي ابْنَ كَثِيرٍ - حَدَّثَنِي نَافِعٌ، أَنَّ عَبْدَ اللَّهِ بْنَ عُمَرَ، - رضى الله عنهما - حَدَّثَهُ أَنَّهُ، سَمِعَ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ فِي يَوْمِ عَاشُورَاءَ
" إِنَّ هَذَا يَوْمٌ كَانَ يَصُومُهُ أَهْلُ الْجَاهِلِيَّةِ فَمَنْ أَحَبَّ أَنْ يَصُومَهُ فَلْيَصُمْهُ وَمَنْ أَحَبَّ أَنْ يَتْرُكَهُ فَلْيَتْرُكْهُ " . وَكَانَ عَبْدُ اللَّهِ - رضى الله عنه - لاَ يَصُومُهُ إِلاَّ أَنْ يُوَافِقَ صِيَامَهُ .
It is a day on which the people of pre-Islamic days observed fast. So he who liked to fast on this day should do so, and he who liked to abandon it should abandon it. 'Abdullah (Allah be pleased with him) did not observe fast except when it coincided (with the days when he was in the habit of observing voluntary fasts during every month).
Source: Sahih Muslim — repository translation · Imam Muslim ibn al-Hajjaj al-Naysaburi — authenticity/grade metadata requires independent source review · Sunnah.comAudio not available for the selected reciter.
Source: Sahih Muslim — repository arabic · Imam Muslim ibn al-Hajjaj al-Naysaburi · Sunnah.com