To pass wet hands over the whole head during ablution

Narrated Yahya Al-Mazini: A person asked `Abdullah bin Zaid who was the grandfather of `Amr bin Yahya, "Can you show me how Allah's Messenger (ﷺ) used to perform ablution?" `Abdullah bin Zaid replied in the affirmative and asked for water. He poured it on his hands and washed them twice, then he rinsed his mouth thrice and washed his nose with water thrice by putting water in it and blowing it out. He washed his face thrice and after that he washed his forearms up to the elbows twice and then passed his wet hands over his head from its front to its back and vice versa (beginning from the front and taking them to the back of his head up to the nape of the neck and then brought them to the front again from where he had started) and washed his feet (up to the ankles).