Sayyiduna al-Mughirah bin Shu'bah (may Allah be pleased with him) said: I went out with the Messenger of Allah (peace and blessings be upon him). He (peace and blessings be upon him) stood up to relieve himself, and he (peace and blessings be upon him) was wearing a Roman cloak. Then he (peace and blessings be upon him) performed ablution (wudu) and wiped over his leather socks, and said: "I put them on in a state of purity."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17996