Hadithcore
Bulugh al-Maram, 34

Narrated ‘Ali (rad) regarding the description of the ablution of the Prophet (ﷺ):

He (the Prophet) wiped his head (with water) only once. [Reported by Abu Da’ud, An-Nasa’i, AtTirmidhi with a Sahih Sanad (authentic chain of narrators). At-Tirmidhi said, “It’s the most Hadith on this subject”].

وَعَنْ عَلِيٍّ ‏- رضى الله عنه ‏- ‏-فِي صِفَةِ وُضُوءِ اَلنَّبِيِّ صَلَّى اَللَّهُ عَلَيْهِ وَسَلَّمَ‏- قَالَ: { وَمَسَحَ بِرَأْسِهِ وَاحِدَةً.‏ } أَخْرَجَهُ أَبُو دَاوُد َ [1]‏ .‏

References2 variants
In-Book Reference
Book 1, Hadith 39
English Reference
Book 1, Hadith 38