سنن ابن ماجه

It was narrated that Aswad said: “ ‘Abdullah (bin Mas’ud) said: ‘None of you should apportion within himself a part (of his prayer) thinking that it is a right of Allah upon him that he must only turn to his right to leave after finishing the prayer. I saw the Messenger of Allah (ﷺ) and most of the time he turned to his left.’”