Hadith 2046

Mu'adha al-‘Adawiya said she asked ‘A'isha whether God’s messenger used to fast three days every month, and she replied that he did. She asked which days in the month he fasted, and she replied that he did not care which days of the month he fasted. Muslim transmitted it.

وَعَنْ مُعَاذَةَ الْعَدَوِيَّةِ أَنَّهَا سَأَلَتْ عَائِشَةَ: أَكَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَصُومُ مِنْ كُلِّ شَهْرٍ ثَلَاثَةَ أَيَّامٍ؟ قَالَتْ: نَعَمْ فَقُلْتُ لَهَا: مِنْ أَيِّ أَيَّامِ الشَّهْرِ كَانَ يَصُومُ؟ قَالَتْ: لَمْ يَكُنْ يُبَالِي مِنْ أَيِّ أَيَّام الشَّهْر يَصُوم. رَوَاهُ مُسلم

Reference: 5620460
In-book reference: Book 7, Hadith 2046