(50) باب صِفَةِ وُضُوءِ النَّبِيِّ صلى الله عليه وسلم
'Abd al-Rahman al-TamiI reported:
Ibn Abi Mulaikah was asked about ablution. He said : I saw 'Uthman b. 'Affan who was asked about ablution. He called for water. A vessel was then brought to him. He inclined it towords his right hand (poured water upon it). He then put it in the water three times, and washed his face three times. He then put his hand in the water and took it out; then he wiped his head and ears, in and out only once. He then washed his feet, and said : Where are those who asked me to perform ablution? I saw the Messenger of Allah (ﷺ) performing ablution like that. Abu Dawud said : All the sound traditions narrated by ' Uthman indicated that the head is to be wiped once, because they mentioned (the washing of each part in) ablution three times. In their versions of tradition they mentioned the wordings: "he wiped his head." In this case they did not mention any number as they did in other cases.
Reference: Sunan Abi Dawud 108
In-book reference: Book 1, Hadith 108
English translation: Book 1, Hadith 108