The Messenger of Allah ﷺ said, "Allah has angels who roam the earth, conveying to me the greetings of peace from my ummah."
حدثنا ابن نمير أنبأنا سفيان عن عبد الله بن السائب عن زاذان قال
قال رسول الله ﷺ إن لله ملائكة في الأرض سياحين يبلغوني من أمتي السلام
Its isnad is sahih. Abdullah bin Saaib Kindi is trustworthy, and he was deemed trustworthy by Ibn Main, Abu Hatim, Nasai, and others. Zazan is Abu Umar Kindi, whose trustworthiness was already established at 641. Nasai narrated the hadith at 1:189 with chains of transmission through Sufyan Thawri. It also appears in Majma al-Zawaid 9:24 at greater length, where it says, Bazzar narrated it, and its narrators are the narrators of the Sahih.