Mu'jam Kabir Tabarani 16837 — in the time of Mu'awiyah some people

It is narrated from Muhammad bin Ka'b (may Allah have mercy on him) that in the time of Mu'awiyah (may Allah be pleased with him) some people would attend the Fajr prayer and sit with the storyteller of the congregation; then, when the salam was given, they would move to a corner of the mosque and remember Allah and recite the Book of Allah until the day was well advanced. Mu'awiyah (may Allah be pleased with him) was told about them, so he came hurrying or walking briskly until he stopped beside them and said: I have come to give you the glad tidings from Allah concerning what He has granted you: In the time of the Messenger of Allah (peace and blessings be upon him) there were some people (I think he said: they used to do something like what you do); then the Messenger of Allah (peace and blessings be upon him) came (as though I am imitating his walk) until he stopped beside them and said: "Rejoice! By the One in whose hand is my soul, Allah, the Mighty and Majestic, boasts of you before the angels."