(7) باب قضاء الحاجة
and its Asl (original source) is in Abu Da'ud and At-Tirmidhi and Ibn Khuzaima graded it Sahih (sound) through Abu Huraira (rad) without mentioning the "stones".] (ID)
Reference (ID): Bulugh al-Maram 108 (ID)
In-book reference (ID): Book 1, Hadith 127 (ID)
English translation (ID): Book 1, Hadith 114 (ID)