Language:
كتاب الغسل
5
Bathing (Ghusl)
(29)
Chapter: Washing away what comes out from the private parts of a woman (woman's discharge) if one gets soiled with that
(29)
باب غَسْلِ مَا يُصِيبُ مِنْ فَرْجِ الْمَرْأَةِ
Sahih al-Bukhari 293

Narrated Ubai bin Ka`b:

I asked Allah's Messenger (ﷺ) about a man who engages in sexual intercourse with his wife but does not discharge. He replied, "He should wash the parts which comes in contact with the private parts of the woman, perform ablution and then pray." (Abu `Abdullah said, "Taking a bath is safer and is the last order.")

حَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا يَحْيَى، عَنْ هِشَامِ بْنِ عُرْوَةَ، قَالَ أَخْبَرَنِي أَبِي قَالَ، أَخْبَرَنِي أَبُو أَيُّوبَ، قَالَ أَخْبَرَنِي أُبَىُّ بْنُ كَعْبٍ، أَنَّهُ قَالَ يَا رَسُولَ اللَّهِ إِذَا جَامَعَ الرَّجُلُ الْمَرْأَةَ فَلَمْ يُنْزِلْ قَالَ ‏ "‏ يَغْسِلُ مَا مَسَّ الْمَرْأَةَ مِنْهُ، ثُمَّ يَتَوَضَّأُ وَيُصَلِّي ‏"‏‏.‏
قَالَ أَبُو عَبْدِ اللَّهِ الْغَسْلُ أَحْوَطُ، وَذَاكَ الآخِرُ، وَإِنَّمَا بَيَّنَّا لاِخْتِلاَفِهِمْ‏.‏
Reference : Sahih al-Bukhari 293
In-book reference : Book 5, Hadith 45
USC-MSA web (English) reference : Vol. 1, Book 5, Hadith 292
  (deprecated numbering scheme)