Language:
كتاب الوضوء
4  
Ablutions (Wudu')
(34)
Chapter: Whosoever considers not to repeat ablution except if something is discharged or passed from exit (front or back private parts)
(34)
باب مَنْ لَمْ يَرَ الْوُضُوءَ إِلاَّ مِنَ الْمَخْرَجَيْنِ، مِنَ الْقُبُلِ وَالدُّبُرِ
Sahih al-Bukhari 180

Narrated Abu Sa`id Al-Khudri:

Allah's Messenger (ﷺ) sent for a Ansari man who came with water dropping from his head. The Prophet (ﷺ) said, "Perhaps we have forced you to hurry up, haven't we?" The Ansari replied, "Yes." Allah's Messenger (ﷺ) further said, "If you are forced to hurry up (during intercourse) or you do not discharge then ablution is due on you (This order was canceled later on, i.e. one has to take a bath).

حَدَّثَنَا إِسْحَاقُ، قَالَ أَخْبَرَنَا النَّضْرُ، قَالَ أَخْبَرَنَا شُعْبَةُ، عَنِ الْحَكَمِ، عَنْ ذَكْوَانَ أَبِي صَالِحٍ، عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم أَرْسَلَ إِلَى رَجُلٍ مِنَ الأَنْصَارِ فَجَاءَ وَرَأْسُهُ يَقْطُرُ، فَقَالَ النَّبِيُّ صلى الله عليه وسلم ‏"‏ لَعَلَّنَا أَعْجَلْنَاكَ ‏"‏‏.‏ فَقَالَ نَعَمْ‏.‏ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ إِذَا أُعْجِلْتَ أَوْ قُحِطْتَ، فَعَلَيْكَ الْوُضُوءُ ‏"‏‏.‏ تَابَعَهُ وَهْبٌ قَالَ حَدَّثَنَا شُعْبَةُ‏.‏ قَالَ أَبُو عَبْدِ اللَّهِ وَلَمْ يَقُلْ غُنْدَرٌ وَيَحْيَى عَنْ شُعْبَةَ الْوُضُوءُ‏.‏
Reference : Sahih al-Bukhari 180
In-book reference : Book 4, Hadith 46
USC-MSA web (English) reference : Vol. 1, Book 4, Hadith 180
  (deprecated numbering scheme)