Imam Abu Dawud : 2086
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مَسْلَمَةَ عَنْ مَالِكٍ عَنْ هِشَامِ بْنِ عُرْوَةَ عَنْ أَبِيهِ عَنْ عَائِشَةَ رَضِيَ اللَّهُ عَنْهَا قَالَتْ كَانَ يَوْمُ عَاشُورَاءَ يَوْمًا تَصُومُهُ قُرَيْشٌ فِي الْجَاهِلِيَّةِ وَكَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَصُومُهُ فِي الْجَاهِلِيَّةِ فَلَمَّا قَدِمَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ الْمَدِينَةَ صَامَهُ وَأَمَرَ بِصِيَامِهِ فَلَمَّا فُرِضَ رَمَضَانُ كَانَ هُوَ الْفَرِيضَةُ وَتُرِكَ عَاشُورَاءُ فَمَنْ شَاءَ صَامَهُ وَمَنْ شَاءَ تَرَكَهُ
Narrated to us [Abdullah bin Maslamah], from [Malik], from [Hisyam bin 'Urwah], from his father, from [Aisyah] radliallahu 'anha, she said: The day of 'Asyura was fasted by Quraisy during Jahiliyah, and Rasulullah shallallahu 'alaihi wasallam fasted it in Jahiliyah. When he came to Madinah, he fasted it and ordered its fasting. When Ramadhan was obligated, it became the obligatory fast, and 'Asyura was left. Whoever wishes may fast it; whoever wishes may leave it.