Beautiful Hadith is about Ablution Before Ghusl

Narrated `Aisha RA: Whenever the Prophet (peace be upon him) 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. (Bukhari - Vol. 1, Book 5, Hadith 248)