Muwatta Malik, Book 18, Hadith 643 (In-Book) ⓘ

Yahya related to me from Malik from Abd Rabbih ibn Said from Abu Bakr ibn Abd ar-Rahman ibn al-Harith ibn Hisham from A'isha and Umm Salama, the wives of the Prophet, may Allah bless him and grant him peace, that the Prophet, may Allah bless him and grant him peace, used to get up in the morning junub from intercourse, not a dream, in Ramadan, and then he would fast."

وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ عَبْدِ رَبِّهِ بْنِ سَعِيدٍ، عَنْ أَبِي بَكْرِ بْنِ عَبْدِ الرَّحْمَنِ بْنِ الْحَارِثِ بْنِ هِشَامٍ، عَنْ عَائِشَةَ، وَأُمِّ سَلَمَةَ زَوْجَىِ النَّبِيِّ صلى الله عليه وسلم أَنَّهُمَا قَالَتَا كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يُصْبِحُ جُنُبًا مِنْ جِمَاعٍ غَيْرِ احْتِلاَمٍ فِي رَمَضَانَ ثُمَّ يَصُومُ ‏.‏