Sahih Muslim Book - 3, Hadith - 786

حَدَّثَنَا هَارُونُ بْنُ مَعْرُوفٍ وَهَارُونُ بْنُ سَعِيدٍ الْأَيْلِيُّ قَالَا حَدَّثَنَا ابْنُ وَهْبٍ أَخْبَرَنِي عِيَاضُ بْنُ عَبْدِ اللَّهِ عَنْ أَبِي الزُّبَيْرِ عَنْ جَابِرِ بْنِ عَبْدِ اللَّهِ عَنْ أُمِّ كُلْثُومٍ عَنْ عَائِشَةَ زَوْجِ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَتْ إِنَّ رَجُلًا سَأَلَ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ عَنْ الرَّجُلِ يُجَامِعُ أَهْلَهُ ثُمَّ يُكْسِلُ هَلْ عَلَيْهِمَا الْغُسْلُ وَعَائِشَةُ جَالِسَةٌ فَقَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ إِنِّي لَأَفْعَلُ ذَلِكَ أَنَا وَهَذِهِ ثُمَّ نَغْتَسِلُ.

It was narrated that 'Aishah, the wife of the Prophet (s.a.w), said: "A man asked the Messenger of Allah (s.a.w) about a man who has intercourse with his wife then he fails (to ejaculate). Do they have to perform Ghusl? 'Aishah was sitting there, and the Messenger of Allah (s.a.w) said: 'I do that, I and this one, then we perform Ghusl."'