حَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا يَحْيَى، عَنْ عُبَيْدِ اللَّهِ، قَالَ أَخْبَرَنِي نَافِعٌ، عَنِ ابْنِ عُمَرَ ـ رضى الله عنهما ـ قَالَ كَانَ عَاشُورَاءُ يَصُومُهُ أَهْلُ الْجَاهِلِيَّةِ، فَلَمَّا نَزَلَ رَمَضَانُ قَالَ " مَنْ شَاءَ صَامَهُ، وَمَنْ شَاءَ لَمْ يَصُمْهُ ".
Narrated Ibn `Umar: Fasting was observed on the day of 'Ashura' (i.e. 10th of Muharram) by the people of the Pre-lslamic Period. But when (the order of compulsory fasting) in the month of Ramadan was revealed, the Prophet said, "It is up to one to fast on it (i.e. day of 'Ashura') or not." Translation Not Available
Book Ref: Sahih Bukhari Book 65 Hadith 4501
Web Ref: Sahih Bukhari Vol 6 Book 60 Hadith 28