(13) باب صِحَّةِ صَوْمِ مَنْ طَلَعَ عَلَيْهِ الْفَجْرُ وَهُوَ جُنُبٌ
'A'isha, the wife of the Messenger of Allah (ﷺ), said:
The dawn broke upon the Messenger of Allah (ﷺ) during the Ramadan in a state of junub not because of sexual dream (but on account of intercourse) and he washed himself and observed fast.
Reference: Sahih Muslim 1109 b
In-book reference: Book 13, Hadith 96
USC-MSA web (English) reference(deprecated numbering scheme): Book 6, Hadith 2452