مُسْنَدُ أَحْمَدَ
Musnad Ahmad 4058
Musnad of Abdullah bin Mas'ood
It was narrated from al-Aswad, from 'Abdullah, who said: No one of you should give a share of himself to the Shaitan by thinking that it is obligatory to leave to the right only (after finishing the prayer). Most of the time I saw The Messenger of Allah (ﷺ) leave to His left.
Musnad Ahmad 4084Its isnad is saheeh, al-Bukhari (852)]