Sahih Muslim Book - 2, Hadith - 629

و حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ وَأَبُو كُرَيْبٍ قَالَ أَبُو بَكْرٍ حَدَّثَنَا أَبُو مُعَاوِيَةَ عَنْ الْأَعْمَشِ عَنْ مُسْلِمٍ عَنْ مَسْرُوقٍ عَنْ الْمُغِيرَةِ بْنِ شُعْبَةَ قَالَ كُنْتُ مَعَ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فِي سَفَرٍ فَقَالَ يَا مُغِيرَةُ خُذْ الْإِدَاوَةَ فَأَخَذْتُهَا ثُمَّ خَرَجْتُ مَعَهُ فَانْطَلَقَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ حَتَّى تَوَارَى عَنِّي فَقَضَى حَاجَتَهُ ثُمَّ جَاءَ وَعَلَيْهِ جُبَّةٌ شَامِيَّةٌ ضَيِّقَةُ الْكُمَّيْنِ فَذَهَبَ يُخْرِجُ يَدَهُ مِنْ كُمِّهَا فَضَاقَتْ عَلَيْهِ فَأَخْرَجَ يَدَهُ مِنْ أَسْفَلِهَا فَصَبَبْتُ عَلَيْهِ فَتَوَضَّأَ وُضُوءَهُ لِلصَّلَاةِ ثُمَّ مَسَحَ عَلَى خُفَّيْهِ ثُمَّ صَلَّى.

It was narrated that Al-Mughirah bin Shu'bah said: "I was with the Prophet (s.a.w) on a journey, and he said: 'O Mughirah, take the container.' So I took it, then I went out with him. The Messenger of Allah (s.a.w) disappeared from my sight and relieved himself, then he came back. He was wearing a Syrian cloak with narrow sleeves, and he tried to bring his arms out through the sleeves, but they were too narrow, so he brought his arms out from underneath it and I poured water for him. He performed Wudu' as for prayer, then he wiped over his Khuff, then he offered prayer."