Musnad Ahmad 32:1571

Hassan narrated to us, Hammad ibn Salamah narrated to us, from Ali ibn Zayd ibn Jud'an, from Anas ibn Malik, who said: The Messenger of Allah, peace and blessings of Allah be upon him, said: "I saw, on the night I was taken on the Night Journey, men whose lips were being clipped with scissors of fire. I said: 'O Gabriel, who are these?' He said: 'These are the preachers of your nation who command people to righteousness and forget themselves, while they recite the Book. Do they not then use their reason?'"