It is narrated from Hazrat Anas (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: On the night of Mi'raj, I passed by some people whose mouths were being cut with scissors of fire. I asked, "Who are these people?" It was said, "These are the preachers of the world who used to enjoin good upon others but forgot themselves, and they used to recite the Book. Did they not understand?"