Bulugh al-Maram, Book 1, Hadith 40 (In-Book)

Narrated ‘Abdullah bin Zaid bin ‘Aasim (rad) describing the nature of ablution performance: Allah’s Messenger wiped his head from the forehead to the back of his head and then back to the forehead with his (wet) hands. [ Agreed upon ].

وَعَنْ عَبْدِ اَللَّهِ بْنِ يَزِيدَ بْنِ عَاصِمٍ ‏- رضى الله عنه ‏- ‏-فِي صِفَةِ اَلْوُضُوءِ‏- قَالَ: { وَمَسَحَ ‏- صلى الله عليه وسلم ‏-بِرَأْسِهِ, فَأَقْبَلَ بِيَدَيْهِ وَأَدْبَرَ.‏ } مُتَّفَقٌ عَلَيْه ِ (45)‏.‏ ‏1 ‏- صحيح.‏ رواه البخاري (186)‏، ومسلم (235)‏.‏

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also referenced under: Book 1, Hadith 39 (English)