It is narrated from Sayyiduna al-Mughirah bin Shu'bah (may Allah be pleased with him) that he (peace and blessings be upon him) "used to wipe over the top and bottom of the khuffs (leather socks)."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 1377