Sunan Ibn Mājah 332✓ 4Sahih
حَدَّثَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ نُمَيْرٍ، حَدَّثَنَا عُمَرُ بْنُ عُبَيْدٍ، عَنْ عُمَرَ بْنِ الْمُثَنَّى، عَنْ عَطَاءٍ الْخُرَاسَانِيِّ، عَنْ أَنَسٍ، قَالَ كُنْتُ مَعَ النَّبِيِّ ـ صلى الله عليه وسلم ـ فِي سَفَرٍ فَتَنَحَّى لِحَاجَتِهِ ثُمَّ جَاءَ فَدَعَا بِوَضُوءٍ فَتَوَضَّأَ .
It was narrated that Anas said:"I was with the Prophet on a journey. He went away to relieve himself, then he came and called for water and performed ablution