Musannaf Ibn Abi Shayba 1:228

Yunus ibn Muhammad narrated to us, from Dawud ibn Abi al-Furat, from Muhammad ibn Zayd, from Abu Shurayh, from Abu Muslim, the freed slave of Zayd ibn Suhan, who said: I was with Salman, and he saw a man taking off his leather socks (khuffayn) for ablution. Salman said to him, "Wipe over your leather socks, your head covering (khimar), and your forelock, for I saw the Messenger of Allah, may Allah bless him and grant him peace, wiping over the leather socks and the head covering."