Abu al-Sa'ib (may Allah have mercy on him) narrates that Mughirah bin Shu'bah (may Allah be pleased with him) said: The Messenger of Allah (peace and blessings be upon him) was on a journey, and Mughirah was also on that journey. He said: One day the Messenger of Allah (peace and blessings be upon him) went to relieve himself, so I followed him (peace and blessings be upon him) with a vessel of water and cleared the way for him (peace and blessings be upon him). He (peace and blessings be upon him) performed ablution and wiped over his leather socks.
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 18204