Sahih Muslim

Sahih Muslim, Hadith 1157b

Book 13: The Book of Fasting
Chapter 34: Chapter: The Prophet's Fasts at times other than Ramadan; and it is recommended to ensure that no month is free of fasting

بَاب صِيَامِ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فِي غَيْرِ رَمَضَانَ وَاسْتِحْبَابِ أَنْ لَا يُخْلِيَ شَهْرًا عَنْ صَوْمٍ

Sahih Muslim 1157bBook 13, Hadith 231

وَحَدَّثَنَا مُحَمَّدُ بْنُ بَشَّارٍ وَأَبُو بَكْرِ بْنُ نَافِعٍ عَنْ غُنْدَرٍ عَنْ شُعْبَةَ عَنْ أَبِي بِشْرٍ بِهَذَا الْإِسْنَادِ وَقَالَ شَهْرًا مُتَتَابِعًا مُنْذُ قَدِمَ الْمَدِينَةَ

This hadith has been narrated on the authority of Abu Bishr with the same chain of transmitters (with a slight variation of words and these are), that he (the narrator) said:

" During any month continuously since he came to Medina."

Read it in place: 13. The Book of Fasting