It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: The idea that disease is contagious is not correct, there is no reality to bad omens, there is no truth to the month of Safar or the owl being inauspicious. (Simak says that "Safar" is a worm in a person's stomach.) A man asked: O Messenger of Allah (peace and blessings be upon him)! Among a hundred camels, if a mangy camel joins them, it makes all of them mangy (and you say that disease is not contagious?) The Prophet (peace and blessings be upon him) said: "Tell me, who caused the first camel to have mange?"