The Prophet (ﷺ) used to say salam to his right and to his left: As-salamu 'alaykum wa rahmatullah, as-salamu alaykum wa rahmatullah (peace be upon you and the mercy of Allah, peace be upon you and the mercy of Allah) until the whiteness of his cheek could be seen from here, and the whiteness of his cheek from here.
Reference: Sunan an-Nasa'i 1324 In-book : Book 13, Hadith 146 English translation : Vol. 2, Book 13, Hadith 1325
Help us gift a modern, ad-free Islamic application for the Muslim Ummah. Your donation will be recorded as Sadaqah Jariyah in your book of deeds, In Sha Allah.