It was narrated from Wiithilah bin Asqa' that the Prophet P.B.U.H said: "Keep your infants, your insane and your evil ones away from your Masjids. Avoid engaging in transactions and disputes, raising your voices, carrying out your prescribed punishments and unsheathing your swords therein. Make places for purification at their gates, and perfume them with incense on Fridays." (Maudhu)