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.’”
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا عَلِيُّ بْنُ مُحَمَّدٍ، حَدَّثَنَا وَكِيعٌ، ح وَحَدَّثَنَا أَبُو بَكْرِ بْنُ خَلاَّدٍ، حَدَّثَنَا يَحْيَى بْنُ سَعِيدٍ، قَالاَ حَدَّثَنَا الأَعْمَشُ، عَنْ عُمَارَةَ، عَنِ الأَسْوَدِ، قَالَ قَالَ عَبْدُ اللَّهِ لاَ يَجْعَلَنَّ أَحَدُكُمْ لِلشَّيْطَانِ فِي نَفْسِهِ جُزْءًا يَرَى أَنَّ حَقًّا لِلَّهِ عَلَيْهِ أَنْ لاَ يَنْصَرِفَ إِلاَّ عَنْ يَمِينِهِ قَدْ رَأَيْتُ رَسُولَ اللَّهِ ـ صلى الله عليه وسلم ـ أَكْثَرُ انْصِرَافِهِ عَنْ يَسَارِهِ .
sunnah.com