The Book Of Purification

 Seclusion While Reliving Oneself

Al-Mughirah bin Shu'bah narrated that when the Prophet (PBUH) would go (to relieve himself), he would go to a distant place.

Reference: Book Of Hadith Name: Sunan Abu Dawud; Hadith No: 01; Chapter No: 01; Volume No: 01; Page No: 24