It is narrated from Sayyiduna al-Mughirah bin Shu'bah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) went out to relieve himself, and Sayyiduna al-Mughirah (may Allah be pleased with him) followed him (peace and blessings be upon him) carrying a vessel of water, and kept pouring water for him (peace and blessings be upon him) until he (peace and blessings be upon him) had finished relieving himself. Then he (peace and blessings be upon him) performed ablution (wudu) and wiped over the leather socks.
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 18000