They both testified that the Prophet ﷺ said, "No group sits remembering Allah except that the angels surround them, mercy covers them, tranquility descends upon them, and Allah mentions them to those with Him."
أنهما شهدا على النبي ﷺ أنه قال: لا يقعد قوم يذكرون الله عز وجل إلا حفتهم الملائكة، وغشيتهم الرحمة، ونزلت عليهم السكينة، وذكرهم الله فيمن عنده.
Muslim narrated it in the Book of Remembrance and Supplication (2700:39) through several routes from Muhammad bin Jafar, who said, Shubah narrated to us, I heard Abu Ishaq narrating from Aghar Abu Muslim, that he said, "I bear witness regarding Abu Hurairah and Abu Saeed Khudri," and he mentioned it.