سُنَنُ النَّسَائِيِّ
Sunan an-Nasa’i 2419
The Book of Fasting
How to Fast Three Days of Each Month, And Mentioning The Differences Reported by The Narrators In The Narration Regarding that
أَخْبَرَنَا إِبْرَاهِيمُ بْنُ سَعِيدٍ الْجَوْهَرِيُّ، قَالَ حَدَّثَنَا مُحَمَّدُ بْنُ فُضَيْلٍ، عَنِ الْحَسَنِ بْنِ عُبَيْدِ اللَّهِ، عَنْ هُنَيْدَةَ الْخُزَاعِيِّ، عَنْ أُمِّهِ، عَنْ أُمِّ سَلَمَةَ، قَالَتْ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يَأْمُرُ بِصِيَامِ ثَلاَثَةِ أَيَّامٍ أَوَّلِ خَمِيسٍ وَالاِثْنَيْنِ وَالاِثْنَيْنِ .
It was narrated that Umm Salamah said: "The Messenger of Allah used to enjoin fasting three days: The first Thursday, and Monday and Monday."
Sunan an-Nasa'i, 2419Sahih (Darussalam)