(84) باب ذِكْرِ الاِخْتِلاَفِ عَلَى مُوسَى بْنِ طَلْحَةَ فِي الْخَبَرِ فِي صِيَامِ ثَلاَثَةِ أَيَّامٍ مِنَ الشَّهْرِ
It was narrated from Abu Dharr that the Prophet said to a man:
"You should fast the thirteenth, fourteenth and fifteenth." (Hasan)Abu 'Abdur-Rahman (An-Nasai) said: This is a mistake, it is not a narration of Bayan; perhaps Sufyan said: "It was narrated to us by two (Ithnan)" and the 'Alif was dropped so it became Bayan.
Reference: Sunan an-Nasa'i 2425
In-book reference: Book 22, Hadith 336
English translation: Vol. 3, Book 22, Hadith 2427