It was narrated from 'Urwah bin Mughirah bin Shu'bah from his father Mughirah bin Shu'bah, that:The Messenger of Allah went out to relieve himself, and Mughirah followed him with a vessel of water. When he finished relieving himself, he performed ablution and wiped over his leather socks.
حَدَّثَنَا مُحَمَّدُ بْنُ رُمْحٍ، أَنْبَأَنَا اللَّيْثُ بْنُ سَعْدٍ، عَنْ يَحْيَى بْنِ سَعِيدٍ، عَنْ سَعْدِ بْنِ إِبْرَاهِيمَ، عَنْ نَافِعِ بْنِ جُبَيْرٍ، عَنْ عُرْوَةَ بْنِ الْمُغِيرَةِ بْنِ شُعْبَةَ، عَنْ أَبِيهِ الْمُغِيرَةِ بْنِ شُعْبَةَ، عَنْ رَسُولِ اللَّهِ ـ صلى الله عليه وسلم ـ أَنَّهُ خَرَجَ لِحَاجَتِهِ فَاتَّبَعَهُ الْمُغِيرَةُ بِإِدَاوَةٍ فِيهَا مَاءٌ حَتَّى فَرَغَ مِنْ حَاجَتِهِ فَتَوَضَّأَ وَمَسَحَ عَلَى الْخُفَّيْنِ .
IbnMaja
The Book of Purification and its Sunnah • Hadith 545