Musnad Ahmad 435:27

Ali ibn Bahr narrated to us, al-Walid ibn Muslim narrated to us, he said: Abdullah ibn al-Ala narrated to us, from Abu al-Azhar, from Muawiyah, that he mentioned to them the ablution of the Messenger of Allah, peace and blessings of Allah be upon him, and that he wiped his head with a handful of water until the water dripped from his head, or nearly dripped. And that he showed them the ablution of the Messenger of Allah, peace and blessings of Allah be upon him. When he reached the wiping of his head, he placed his palms on the front of his head, then he passed them until he reached the nape of the neck, then he returned them until he reached the place from which he began.