Ablutions (Wudu')
4/22. Chapter:
The washing of the body parts (i.e., the parts which are washed in ablution) once only while performing ablution
Sahih Bukhari
حَدَّثَنَا مُحَمَّدُ بْنُ يُوسُفَ، قَالَ حَدَّثَنَا سُفْيَانُ، عَنْ زَيْدِ بْنِ أَسْلَمَ، عَنْ عَطَاءِ بْنِ يَسَارٍ، عَنِ ابْنِ عَبَّاسٍ، قَالَ تَوَضَّأَ النَّبِيُّ صلى الله عليه وسلم مَرَّةً مَرَّةً.
Narrated Ibn `Abbas: The Prophet (ﷺ) performed ablution by washing the body parts only once.
Reference : Sahih al-Bukhari 157In-book reference : Book 4, Hadith 23USC-MSA web (English) reference : Vol. 1, Book 4, Hadith 159