The Book of Prayers (Kitab Al-Salat)
Muslim :: Book 4 : Hadith 1529
Bara' reported: When we prayed behind the Messenger of Allah (may peace be upon him) we cherished to be on his right side so that his face would turn towards us (at the end of the prayer), and he (the narrator) said: I heard him say: O my Lord! save me from Thy torment on the Day when Thoil, wouldst raise or gather Thy servants.