It wasnarrated from 'Abdullah that the Messenger of Allah (ﷺ) usedtosay the Salam to his right and his left, until the whiteness of hischeek could be seen (saying):
"As-salamu 'alaikum wa rahmatullah(Peace be upon you and the mercy of Allah)." (DE)
English reference (DE): Vol. 1, Book 5, Hadith 914 (DE)
Arabic reference (DE): Book 5, Hadith 967 (DE)