Abu Ubaydah bin Muhammad bin Ammar bin Yasir said: I asked Sayyiduna Jabir bin Abdullah (may Allah be pleased with him) about wiping over the khuffs (leather socks), and he said: "My nephew, that is the Sunnah." I asked him about wiping over the turban, and he said: "No, I let the water touch the hair."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 284