Musnad Ahmad 443:1

Abu al-Mughirah narrated to us, Hariz ibn Uthman al-Rahbi narrated to us, he said: I heard Abdullah ibn Ghabir al-Alhani say: Habis ibn Sa’d al-Ta’i—who had met the Prophet (peace be upon him)—entered the mosque at the time of the pre-dawn (al-sahar). He saw people praying in the front of the mosque, so he said: "They are show-offs, by the Lord of the Kaaba. Frighten them, for whoever frightens them has obeyed Allah and His Messenger." So the people came to them and drove them out. He said: Then he said: "Indeed, the angels pray from the time of the pre-dawn in the front of the mosque."