I was with the Messenger of Allah ﷺ on one of his journeys. Whenever he went to relieve himself, he would go far away. He went off to attend to his need and said, "Mughirah, follow me with water." Then he mentioned the rest of the hadith.
حدثنا محمد بن عبيد حدثنا محمد بن عمرو عن أبي سلمة
كنت مع رسول الله ﷺ في بعض أسفاره وكان إذا ذهب أبعد في المذهب فذهب لحاجته وقال يا مغيرة اتبعني بماء فذكر الحديث
No references are available.
Its isnad is sahih, and Muhammad bin Amr bin Alqama is trustworthy, and his hadith is found in the collections of all six. Abu Salama is Ibn Abdul-Rahman, the well-known imam. The hadith has already appeared at 18052.