Fasting
30/25. Chapter:
Taking a bath by a person observing Saum (fast)
Sahih Bukhari
حَدَّثَنَا إِسْمَاعِيلُ، قَالَ حَدَّثَنِي مَالِكٌ، عَنْ سُمَىٍّ، مَوْلَى أَبِي بَكْرِ بْنِ عَبْدِ الرَّحْمَنِ بْنِ الْحَارِثِ بْنِ هِشَامِ بْنِ الْمُغِيرَةِ أَنَّهُ سَمِعَ أَبَا بَكْرِ بْنَ عَبْدِ الرَّحْمَنِ، كُنْتُ أَنَا وَأَبِي،، فَذَهَبْتُ مَعَهُ، حَتَّى دَخَلْنَا عَلَى عَائِشَةَ ـ رضى الله عنها ـ قَالَتْ أَشْهَدُ عَلَى رَسُولِ اللَّهِ صلى الله عليه وسلم إِنْ كَانَ لَيُصْبِحُ جُنُبًا مِنْ جِمَاعٍ غَيْرِ احْتِلاَمٍ، ثُمَّ يَصُومُهُ. ثُمَّ دَخَلْنَا عَلَى أُمِّ سَلَمَةَ، فَقَالَتْ مِثْلَ ذَلِكَ.
Narrated Abu Bakr bin `Abdur-Rahman: My father and I went to `Aisha and she said, "I testify that Allah's Messenger (ﷺ) at times used to get up in the morning in a state of Janaba from sexual intercourse, not from a wet dream and then he would fast that day." Then he went to Um Salama and she also narrated a similar thing.
Reference : Sahih al-Bukhari 1931, 1932In-book reference : Book 30, Hadith 39USC-MSA web (English) reference : Vol. 3, Book 31, Hadith 153