Sunan Abi Dawud

Narrated Talhah ibn Musarrif: I saw the Messenger of Allah (ﷺ) wiping his head once up to his nape. Musaddad reported: He wiped his head from front to back until he moved his hands from beneath the ears. Abu Dawud said: I heard Ahmad say: People thought that Ibn 'Uyainah had considered it to be munkar (rejected) and said: What is this chain: Talhah - his father - his grandfather ?