Salim bin Abdullah narrates from his father (may Allah be pleased with him) that Sayyiduna Sa'd bin Abi Waqqas (may Allah be pleased with him) asked Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) about wiping over the khuffs (leather socks), and Sayyiduna Umar (may Allah be pleased with him) said: "I heard the Messenger of Allah (peace and blessings be upon him) ordering us to wipe over the upper part of the khuffs when, he said, they had been put on in a state of ablution."
(b) Khalid bin Abi Bakr is not strong, and what has preceded is sufficient.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 1391