It was narrated that ‘Abdullah (رضي الله عنه) said:

When we sat with The Messenger of Allah (ﷺ) in the prayer, we said: Peace be upon Allah before His slaves, peace be upon Jibreel, peace be upon Mika'eel, peace be upon So and so, peace be upon So and so. Then we heard The Messenger of Allah (ﷺ) say: "Allah Himself is as-Salam (peace), so when one of you sits in the prayer, let him say, "All compliments, prayers and pure words are due to Allah. Peace be upon you, O Prophet, and the mercy of Allah and His blessings. Peace be upon us, and upon the righteous slaves of Allah.' If he says that, it will reach all the righteous slaves in heaven and on earth. ‘I bear witness that there is no god but Allah, and I bear witness that Muhammad is His slave and Messenger.’ Then let him choose whatever supplication he wants.”