Sunan at-Tirmidhi (Jami-al-Tirmidhi), Chapter: Taharah (Purification)

narrated that when Allah's Messenger (SAW) decided to have the purifying bath (after sexual defilement), he began by washing both hands before immersing them in the vessel. Then he washed his private parts and made ablution as he made for salah. Then he put his fingers into the water and moved them through his hair and then poured water on his head with both hands three times. [Ahmed25704, Bukhari 248, Muslim 316, Nisai 420]