Sunan al-Nasa'i The Book of Fasting Abu Dharr al-Ghaffari al-Fadl bin Musa al-Synany الفضل بن موسى السيناني Muhammad bin 'Abdul 'Aziz bin al-Wasti محمد بن عبد العزيز العمري الرملي بن الوا Musa ibn Talha Yahya bin Sam يحيى بن سام the Messenger of Allah used to fast nine days of Dhul-Hijjah, the day of ‘Ashura’, and three days of each month: The first Monday of the month, and two Thursday. https://parallelquran.com/hadith/sunan-al-nasai-2422/ Sunan al-Nasa'i The Book of Fasting Abdur Rahman bin Mahdi عبد الرحمن بن مهدي Abu Dharr al-Ghaffari Musa ibn Talha Shu'bah bin al-Hajjaj شعبة بن الحجاج Sulaiman al-A'mash الأعمش / سليمان بن مهران Yahya bin Sam يحيى بن سام “The Prophet used to fast the ten (days), and three days of each month: Monday and Thursday.” https://parallelquran.com/hadith/sunan-al-nasai-2423/ Sunan al-Nasa'i The Book of Fasting Abdur Rahman bin Mahdi عبد الرحمن بن مهدي Musa ibn Talha Shu'bah bin al-Hajjaj شعبة بن الحجاج Sulaiman al-A'mash الأعمش / سليمان بن مهران Yahya bin Sam يحيى بن سام “The Messenger of Allah used to enjoin fasting three days: The first Thursday, and Monday and Monday.” https://parallelquran.com/hadith/sunan-al-nasai-2424/ Jami' al-Tirmidhi The Book on Fasting Abu Da'ud أبو داود السجستاني الأزدي Abu Dharr al-Ghaffari Mahmud bin Ghaylan محمود بن غيلان العدوي مولاهم أبو أحمد Musa ibn Talha Shu'bah bin al-Hajjaj شعبة بن الحجاج Sulaiman al-A'mash الأعمش / سليمان بن مهران Yahya bin Sam يحيى بن سام the Messenger of Allah said: “O Abu Dharr! When you fast three days out of a month, then fast the thirteenth, fourteenth, and fifteenth.” https://parallelquran.com/hadith/jami-al-tirmidhi-761/