Sahih Muslim 2645
صحيح مسلم#2645Sahihحَدَّثَنَا 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 .
Abdullah b. 'Umar (Allah be pleased with both of them) reported that he heard the Messenger of Allah (ﷺ) say about the day of Ashura: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)
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Every narration in Sahih Muslim is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 13:151