Sunan Ibn Majah, Book 1, Hadith 356 (In-Book) ⓘ
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."
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 .
also referenced under: Hadith 332 (Reference) & Volume 1, Book 1, Hadith 332 (DarusSalam)