Simak (may Allah have mercy on him) says: I heard Nu'man (may Allah be pleased with him), wrapped in a cloak, saying during a sermon that I heard the Prophet Muhammad (peace and blessings be upon him) delivering a sermon, and he was saying: I have warned you about Hell. If a person were at such and such a distance, even then he would have heard the voice of the Prophet Muhammad (peace and blessings be upon him).