My father and I went to ʿAisha and she said, "I testify that Messenger of Allah 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.
أَشْهَدُ عَلَى رَسُولِ اللَّهِ ﷺ إِنْ كَانَ لَيُصْبِحُ جُنُبًا مِنْ جِمَاعٍ غَيْرِ احْتِلاَمٍ ثُمَّ يَصُومُهُ ثُمَّ دَخَلْنَا عَلَى أُمِّ سَلَمَةَ فَقَالَتْ مِثْلَ ذَلِكَ
The Messenger of Allah ﷺ at times got up in the morning in a state of junub on account of having a sexual intercourse (with his wives during night) but not due to sexual dreams in the month of Ramadan, and would observe fast.
عَنْ عَائِشَةَ وَأُمِّ سَلَمَةَ زَوْجَىِ النَّبِيِّ ﷺ أَنَّهُمَا قَالَتَا إِنْ كَانَ رَسُولُ اللَّهِ ﷺ لَيُصْبِحُ جُنُبًا مِنْ جِمَاعٍ غَيْرِ احْتِلاَمٍ فِي رَمَضَانَ ثُمَّ يَصُومُ
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 ﷺ that the Prophet ﷺ used to get up in the morning junub from intercourse, not a dream, in Ramadan, and then he would fast."
عَنْ عَائِشَةَ وَأُمِّ سَلَمَةَ زَوْجَىِ النَّبِيِّ ﷺ أَنَّهُمَا قَالَتَا كَانَ رَسُولُ اللَّهِ ﷺ يُصْبِحُ جُنُبًا مِنْ جِمَاعٍ غَيْرِ احْتِلاَمٍ فِي رَمَضَانَ ثُمَّ يَصُومُ
Yahya related to me from Malik from Sumayy, the mawla of Abu Bakr, from Abu Bakr ibn Abd ar-Rahman that A'isha and Umm Salama, the wives of the Prophet ﷺ said, "The Messengerof Allah ﷺ used to get up in the morning junub from intercourse, not a dream, and would then fast."
عَنْ عَائِشَةَ وَأُمِّ سَلَمَةَ زَوْجَىِ النَّبِيِّ ﷺ أَنَّهُمَا قَالَتَا إِنْ كَانَ رَسُولُ اللَّهِ ﷺ لَيُصْبِحُ جُنُبًا مِنْ جِمَاعٍ غَيْرِ احْتِلاَمٍ ثُمَّ يَصُومُ