It was narrated that Abu Muslim, the freed slave of Zaid bin Suhan, said:
"I was with Salman, and he saw a man removing his leather socks for ablution. Salman said to him" 'Wipe over your leather socks and your head cover, and your forehead, for I saw the Messenger of Allah wiping over his leather socks and head cover.'" (IT)
English reference (IT): Vol. 1, Book 1, Hadith 563 (IT)
Arabic reference (IT): Book 1, Hadith 606 (IT)