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).

To pass wet hands over the whole head during ablution

Narrated Abu Juhaifa:

Allah's Messenger (ﷺ) came to us at noon and water for ablution was brought to him. After he had performed ablution, the remaining water was taken by the people and they started smearing their bodies with it (as a blessed thing). The Prophet (ﷺ) offered two rak`at of the Zuhr prayer and then two rak`at of the `Asr prayer while a short spear (or stick) was there (as a Sutra) in front of him.

To pass wet hands over the whole head during ablution

Narrated As-Sa'ib bin Yazid:

My aunt took me to the Prophet (ﷺ) and said, "O Allah's Messenger (ﷺ)! This son of my sister has got a disease in his legs." So he passed his hands on my head and prayed for Allah's blessings for me; then he performed ablution and I drank from the remaining water. I stood behind him and saw the seal of Prophethood between his shoulders, and it was like the "Zir-al-Hijla" (means the button of a small tent, but some said 'egg of a partridge.' etc.)