مُسْنَدُ أَحْمَدَ
Musnad Ahmad 1564
Musnad Abu Ishaq Sa'd bin Abi Waqqas
It was narrated from "Amir bin Sa"d, that his father Sa"d bin Malik said: The Prophet (ﷺ) used to say salam to his right and to his left (at the end of the prayer, turning his head) so much that the whiteness of his cheeks could be seen.
Musnad Ahmad 1564Sahih Hadeeth]