The Messenger of Allah ﷺ said, "Allah has angels who roam the earth, conveying to me the greetings of peace from my ummah."
قال رسول الله ﷺ: إن الله ملائكة سياحين في الأرض يبلغون من أمتي السلام.
Nasai (1282) and Ahmad (3666) narrated it, and Ibn Hibban (914) and Hakim (2/421) graded it sahih, all of them through routes from Sufyan, from Abdullah bin Saaib, from Zazan, from Abdullah bin Masud, who mentioned it. Its chain of transmission is sahih, and Ibn Qayyim also graded it sahih in Jala Afham (p. 120). This is one of the special characteristics of the Prophet ﷺ, that Allah has appointed an angel to convey to him the prayers of those who pray upon him and the greetings of those who greet him with peace.