Language:
كتاب الوضوء
4
Ablutions (Wudu')
(35)
Chapter: (What is said regarding) a man who helps his companion to perform ablution (by pouring water for him)
(35)
باب الرَّجُلِ يُوَضِّئُ صَاحِبَهُ

Narrated Al-Mughira bin Shu`ba:

I was in the company of Allah's Messenger (ﷺ) on one of the journeys and he went out to answer the call of nature (and after he finished) I poured water and he performed ablution; he washed his face, forearms and passed his wet hand over his head and over the two Khuff (socks made from thick fabric or leather).

حَدَّثَنَا عَمْرُو بْنُ عَلِيٍّ، قَالَ حَدَّثَنَا عَبْدُ الْوَهَّابِ، قَالَ سَمِعْتُ يَحْيَى بْنَ سَعِيدٍ، قَالَ أَخْبَرَنِي سَعْدُ بْنُ إِبْرَاهِيمَ، أَنَّ نَافِعَ بْنَ جُبَيْرِ بْنِ مُطْعِمٍ، أَخْبَرَهُ أَنَّهُ، سَمِعَ عُرْوَةَ بْنَ الْمُغِيرَةِ بْنِ شُعْبَةَ، يُحَدِّثُ عَنِ الْمُغِيرَةِ بْنِ شُعْبَةَ، أَنَّهُ كَانَ مَعَ رَسُولِ اللَّهِ صلى الله عليه وسلم فِي سَفَرٍ، وَأَنَّهُ ذَهَبَ لِحَاجَةٍ لَهُ، وَأَنَّ مُغِيرَةَ جَعَلَ يَصُبُّ الْمَاءَ عَلَيْهِ، وَهُوَ يَتَوَضَّأُ، فَغَسَلَ وَجْهَهُ وَيَدَيْهِ وَمَسَحَ بِرَأْسِهِ وَمَسَحَ عَلَى الْخُفَّيْنِ‏.‏
Reference : Sahih al-Bukhari 182
In-book reference : Book 4, Hadith 48
USC-MSA web (English) reference : Vol. 1, Book 4, Hadith 182
  (deprecated numbering scheme)