Sahih al-Bukhari 363
Narrated Mughira bin Shu`ba:
Once I was traveling with the Prophet (ﷺ) and he said, "O Mughira! take this container of water." I took it 
and Allah's Messenger (ﷺ) went far away till he disappeared. He answered the call of nature and was wearing 
a Syrian cloak. He tried to take out his hands from its sleeve but it was very tight so he took out his 
hands from under it. I poured water and he performed ablution like that for prayers and passed his wet 
hands over his Khuff (socks made from thick fabric or leather) and then prayed .
حَدَّثَنَا يَحْيَى، قَالَ حَدَّثَنَا أَبُو مُعَاوِيَةَ، عَنِ الأَعْمَشِ، عَنْ مُسْلِمٍ، عَنْ مَسْرُوقٍ، عَنْ مُغِيرَةَ بْنِ شُعْبَةَ، قَالَ كُنْتُ مَعَ النَّبِيِّ صلى الله عليه وسلم فِي سَفَرٍ فَقَالَ ‏
"‏ يَا مُغِيرَةُ، خُذِ الإِدَاوَةَ ‏"‏‏.‏ فَأَخَذْتُهَا فَانْطَلَقَ رَسُولُ اللَّهِ صلى الله عليه وسلم حَتَّى تَوَارَى عَنِّي فَقَضَى حَاجَتَهُ، وَعَلَيْهِ جُبَّةٌ شَأْمِيَّةٌ، فَذَهَبَ لِيُخْرِجَ يَدَهُ مِنْ كُمِّهَا فَضَاقَتْ، فَأَخْرَجَ يَدَهُ مِنْ أَسْفَلِهَا، فَصَبَبْتُ عَلَيْهِ فَتَوَضَّأَ وُضُوءَهُ لِلصَّلاَةِ، وَمَسَحَ عَلَى خُفَّيْهِ، ثُمَّ صَلَّى‏.‏