سُنَنُ النَّسَائِيِّ
Sunan an-Nasa’i 2413
The Book of Fasting
Mentioning The Differences Reported From Abu 'Uthman In The Hadith Of Abu Hurairah Regarding Fasting Three Days Out Of Each Month
أَخْبَرَنَا يُوسُفُ بْنُ سَعِيدٍ، قَالَ حَدَّثَنَا حَجَّاجٌ، عَنْ شَرِيكٍ، عَنِ الْحُرِّ بْنِ صَيَّاحٍ، قَالَ سَمِعْتُ ابْنَ عُمَرَ، يَقُولُ كَانَ النَّبِيُّ صلى الله عليه وسلم يَصُومُ ثَلاَثَةَ أَيَّامٍ مِنْ كُلِّ شَهْرٍ .
It was narrated that Al-Hurr bin Sayyah said: "I heard Ibn 'Umar say" "The Prophet (ﷺ) used to fast three days of each month.
Sunan an-Nasa'i, 2413Sahih (Darussalam)