Language:
كتاب الغسل
5  
Bathing (Ghusl)
(1)
Chapter: The performance of ablution before taking a bath
(1)
باب الْوُضُوءِ قَبْلَ الْغُسْلِ
Sahih al-Bukhari 249

Narrated Maimuna:

(the wife of the Prophet) Allah's Messenger (ﷺ) performed ablution like that for the prayer but did not wash his feet. He washed off the discharge from his private parts and then poured water over his body. He withdrew his feet from that place (the place where he took the bath) and then washed them. And that was his way of taking the bath of Janaba.

حَدَّثَنَا مُحَمَّدُ بْنُ يُوسُفَ، قَالَ حَدَّثَنَا سُفْيَانُ، عَنِ الأَعْمَشِ، عَنْ سَالِمِ بْنِ أَبِي الْجَعْدِ، عَنْ كُرَيْبٍ، عَنِ ابْنِ عَبَّاسٍ، عَنْ مَيْمُونَةَ، زَوْجِ النَّبِيِّ صلى الله عليه وسلم قَالَتْ تَوَضَّأَ رَسُولُ اللَّهِ صلى الله عليه وسلم وُضُوءَهُ لِلصَّلاَةِ غَيْرَ رِجْلَيْهِ، وَغَسَلَ فَرْجَهُ، وَمَا أَصَابَهُ مِنَ الأَذَى، ثُمَّ أَفَاضَ عَلَيْهِ الْمَاءَ، ثُمَّ نَحَّى رِجْلَيْهِ فَغَسَلَهُمَا، هَذِهِ غُسْلُهُ مِنَ الْجَنَابَةِ‏.‏
Reference : Sahih al-Bukhari 249
In-book reference : Book 5, Hadith 2
USC-MSA web (English) reference : Vol. 1, Book 5, Hadith 249
  (deprecated numbering scheme)