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suyuti:6657a
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السيوطي:٦٦٥٧a

"إِنَّ عَاشُورَاءَ يَوْمٌ من أيَّام اللَّهِ تَعالى، فَمَنْ شَاءَ صَامَهُ، ومن شَاءَ تركه".  

[حم] أحمد ، [م] مسلم عن ابن عمر

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Collected by Abū Dāwūd
abudawud:2443Musaddad > Yaḥyá > ʿUbaydullāh > Nāfiʿ > Ibn ʿUmar

'Ashurah was a day on which we used to fast in pre-Islamic days. When (fasting of) Ramadan was prescribed, the Messenger of Allah ﷺ said: This is one of the days of Allah ; he who wishes may fast on it.  

أبو داود:٢٤٤٣حَدَّثَنَا مُسَدَّدٌ حَدَّثَنَا يَحْيَى عَنْ عُبَيْدِ اللَّهِ قَالَ أَخْبَرَنِي نَافِعٌ عَنِ ابْنِ عُمَرَ قَالَ

كَانَ عَاشُورَاءُ يَوْمًا نَصُومُهُ فِي الْجَاهِلِيَّةِ فَلَمَّا نَزَلَ رَمَضَانُ قَالَ رَسُولُ اللَّهِ ﷺ هَذَا يَوْمٌ مِنْ أَيَّامِ اللَّهِ فَمَنْ شَاءَ صَامَهُ وَمَنْ شَاءَ تَرَكَهُ