Hadith 2057

Abu Dharr reported God’s messenger as saying, “When you fast three days in the month, Abu Dharr, fast on the thirteenth, fourteenth and fifteenth.” Tirmidhi and Nasa'i transmitted it.

قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «يَا أَبَا ذَرٍّ إِذَا صُمْتَ مِنَ الشَّهْرِ ثَلَاثَةَ أَيَّامٍ فَصُمْ ثَلَاثَ عَشْرَةَ وَأَرْبَعَ عَشْرَةَ وَخَمْسَ عَشْرَةَ» . رَوَاهُ التِّرْمِذِيّ وَالنَّسَائِيّ

Reference: 5620570
In-book reference: Book 7, Hadith 2057