Sahih Bukhari Volume 1, Book 4, Hadith 180

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

Narrated By Abu Said Al-Khudri : Allah's Apostle sent for a Ansari man who came with water dropping from his head. The Prophet said, "Perhaps we have forced you to hurry up, haven't we?" The Ansari replied, "Yes." Allah's Apostle 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 cancelled later on, i.e. one has to take a bath).