Sahih al-Bukhari 157
Sahih al-Bukhari · Book 4: Ablutions (Wudu') · The washing of the body parts (i.e., the parts which are washed in ablution) once only while performing ablution
Narrated Ibn `Abbas:
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.
The Prophet (ﷺ) performed ablution by washing the body parts only once.