Sayyiduna Bilal (may Allah be pleased with him), the freed slave of Abu Bakr (may Allah be pleased with him), reported about the Messenger of Allah (peace and blessings be upon him): "He (peace and blessings be upon him) came back from relieving himself on the day of the Battle of Tabuk, and he (peace and blessings be upon him) called for water and wiped over the leather socks."
Hadith Referenceالمعجم الكبير للطبراني / باب الباء / 1106