حَدَّثَنَا مُسَدَّدٌ حَدَّثَنَا يَحْيَی عَنْ عُبَيْدِ اللَّهِ قَالَ أَخْبَرَنِي نَافِعٌ عَنْ ابْنِ عُمَرَ قَالَ کَانَ عَاشُورَائُ يَوْمًا نَصُومُهُ فِي الْجَاهِلِيَّةِ فَلَمَّا نَزَلَ رَمَضَانُ قَالَ رَسُولُ اللَّهِ صَلَّی اللَّهُ عَلَيْهِ وَسَلَّمَ هَذَا يَوْمٌ مِنْ أَيَّامِ اللَّهِ فَمَنْ شَائَ صَامَهُ وَمَنْ شَائَ تَرَکَهُ
سنن ابودوٗد · Hadith 2443
Ibn Umar said: 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.
Translated by Dr. Muhammad Muhsin Khan · Reviewed by Islamic University of Madinah · Published March 2020