Hadith
"حَدَّثَنَا عَبْدُ اللَّهِ بْنُ يُوسُفَ، قَالَ أَخْبَرَنَا مَالِكٌ، عَنْ هِشَامٍ، عَنْ أَبِيهِ، عَنْ عَائِشَةَ، زَوْجِ النَّبِيِّ صلى الله عليه وسلم أَنَّ النَّبِيَّ صلى الله عليه وسلم كَانَ إِذَا اغْتَسَلَ مِنَ الْجَنَابَةِ بَدَأَ فَغَسَلَ يَدَيْهِ، ثُمَّ يَتَوَضَّأُ كَمَا يَتَوَضَّأُ لِلصَّلاَةِ، ثُمَّ يُدْخِلُ أَصَابِعَهُ فِي الْمَاءِ، فَيُخَلِّلُ بِهَا أُصُولَ شَعَرِهِ ثُمَّ يَصُبُّ عَلَى رَأْسِهِ ثَلاَثَ غُرَفٍ بِيَدَيْهِ، ثُمَّ يُفِيضُ الْمَاءَ عَلَى جِلْدِهِ كُلِّهِ."
Narrated `Aisha:
Whenever the Prophet (ﷺ) took a bath after Janaba he started by washing his hands and then performed ablution like that for the prayer. After that he would put his fingers in water and move the roots of his hair with them, and then pour three handfuls of water over his head and then pour water all over his body.
Sahih
Sahih al-Bukhari, 248
In-Book Reference: Book 5, Hadith 1
USC-MSA web (English) reference: Vol. 1, Book 5, Hadith 248 (deprecated numbering scheme)