Musnad Ahmad 4213

It was narrated from 'Abdullah that The Prophet (ﷺ) used to say the salam to his right and to his left, as-salamu ‘alaikum wa rahmatullah, as-salamu ‘alaikum wa rahmatullah, (turning his face so far that) the whiteness of his cheek could be seen. ‘Abdur-Rahman said: (turning his face so far that) we could see the whiteness of his cheek from here and we could see the whiteness of his cheek from here.