Sahih Muslim Book - 13, Hadith - 2722

وَحَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِى شَيْبَةَ وَعَمْرٌو النَّاقِدُ جَمِيعًا عَنِ ابْنِ عُيَيْنَةَ - قَالَ أَبُو بَكْرٍ حَدَّثَنَا سُفْيَانُ بْنُ عُيَيْنَةَ - عَنِ ابْنِ أَبِى لَبِيدٍ عَنْ أَبِى سَلَمَةَ قَالَ سَأَلْتُ عَائِشَةَ - رضى الله عنها - عَنْ صِيَامِ رَسُولِ اللَّهِ -صلى الله عليه وسلم- فَقَالَتْ كَانَ يَصُومُ حَتَّى نَقُولَ قَدْ صَامَ. وَيُفْطِرُ حَتَّى نَقُولَ قَدْ أَفْطَرَ. وَلَمْ أَرَهُ صَائِمًا مِنْ شَهْرٍ قَطُّ أَكْثَرَ مِنْ صِيَامِهِ مِنْ شَعْبَانَ كَانَ يَصُومُ شَعْبَانَ كُلَّهُ كَانَ يَصُومُ شَعْبَانَ إِلاَّ قَلِيلاً.

It was narrated that Abu Salamah said: “I asked ‘Aishah [may Allah be pleased with her] about the fasting of the Messenger of Allah and she said: ‘He used to fast until we would say: “He has fasted,” and he used not to fast until we would say: “He is not fasting.” And I never saw him fast more in any month than he fasted in Sha’ban. He used to fast all of Sha’ban, he used to fast all of Sha’ban but a little.’’”