Sahih Muslim 1156 c
Abdullah b. Shaqiq reported. I asked 'A'isha (Allah be pleased with her) about fasting of the Messenger of Allah (ﷺ). She said:
He used to observe fast (at times) so continuously that we said: He has fasted, he has fasted. And (at times) he did not observe fast (for days) and we began to say: He has abandoned fasting, he has abandoned fasting. She said: I did not see him observing fast throughout the whole of the month since he arrived in Medina, but that of Ramadan.
وَحَدَّثَنِي أَبُو الرَّبِيعِ الزَّهْرَانِيُّ، حَدَّثَنَا حَمَّادٌ، عَنْ أَيُّوبَ، وَهِشَامٍ، عَنْ مُحَمَّدٍ، عَنْ عَبْدِ اللَّهِ بْنِ شَقِيقٍ، - قَالَ حَمَّادٌ وَأَظُنُّ أَيُّوبَ قَدْ سَمِعَهُ مِنْ عَبْدِ اللَّهِ بْنِ شَقِيقٍ، - قَالَ سَأَلْتُ عَائِشَةَ - رضى الله عنها - عَنْ صَوْمِ النَّبِيِّ صلى الله عليه وسلم فَقَالَتْ كَانَ يَصُومُ حَتَّى نَقُولَ قَدْ صَامَ قَدْ صَامَ ‏.‏ وَيُفْطِرُ حَتَّى نَقُولَ قَدْ أَفْطَرَ قَدْ أَفْطَرَ - قَالَتْ - وَمَا رَأَيْتُهُ صَامَ شَهْرًا كَامِلاً مُنْذُ قَدِمَ الْمَدِينَةَ إِلاَّ أَنْ يَكُونَ رَمَضَانَ ‏.‏