مُسْنَدُ أَحْمَدَ
Musnad Ahmad 4291
Musnad of Abdullah bin Mas'ood
It was narrated that 'Abdullah bin Mas'ood said: The Messenger of Allah (ﷺ) said: "Allah has angels on earth who travel around conveying to me salam from my ummah."
Musnad Ahmad 4320lts isnad is saheeh]