Sunan an-Nasa'i, Volume 3, Book 22, Hadith 2185 (DarusSalam) ⓘ
It was narrated that 'Abdullah bin Shaqiq said: ""I asked 'Aishah about the fasting of the Messenger of Allah. She said: 'The Messenger of Allah used to fast until we said that he is going to fast (continually), and he used not to fast until we said: he is not going to fast. And he did not fast for a whole month from the time he came to Al-Madinah, apart from Ramadan."' '
أَخْبَرَنَا مُحَمَّدُ بْنُ أَحْمَدَ بْنِ أَبِي يُوسُفَ الصَّيْدَلاَنِيُّ، - حَرَّانِيٌّ - قَالَ حَدَّثَنَا مُحَمَّدُ بْنُ سَلَمَةَ، عَنْ هِشَامٍ، عَنِ ابْنِ سِيرِينَ، عَنْ عَبْدِ اللَّهِ بْنِ شَقِيقٍ، عَنْ عَائِشَةَ، قَالَ سَأَلْتُهَا عَنْ صِيَامِ، رَسُولِ اللَّهِ صلى الله عليه وسلم قَالَتْ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يَصُومُ حَتَّى نَقُولَ قَدْ صَامَ وَيُفْطِرُ حَتَّى نَقُولَ قَدْ أَفْطَرَ وَلَمْ يَصُمْ شَهْرًا تَامًّا مُنْذُ أَتَى الْمَدِينَةَ إِلاَّ أَنْ يَكُونَ رَمَضَانُ .
also referenced under: Hadith 2183 (Reference) & Book 22, Hadith 94 (In-Book)