عَنْ مُعَاذَةَ عَنْ عَائِشَةَ رَضِيَ اللَّهُ عَنْهَا أَنَّهَا قَالَتْ: كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ يَصُومُ ثَلَاثَةَ أَيَّامٍ مِنْ كُلِّ شَهْرٍ، قَالَتْ: فَقُلْتُ: مِنْ أَيِّهِ كَانَ؟ فَقَالَتْ: لَمْ يَكُنْ يُبَالِي مِنْ أَيِّهِ كَانَ
It is narrated from Sayyida Mu'adhah (may Allah be pleased with her) that Sayyida Aisha (may Allah be pleased with her) stated that the Messenger of Allah (peace and blessings be upon him) used to fast three days every month. Sayyida Mu'adhah (may Allah be pleased with her) asked: Which three days of the month were those? She said: He (peace and blessings be upon him) did not mind which days they were.