It is narrated from Sayyiduna Ibn Mas'ud (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) stood among us and said: "The concept that disease is contagious is not correct." A Bedouin said: O Messenger of Allah (peace and blessings be upon him)! Among a hundred camels, if one 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 afflicted the first camel with mange? Disease is not contagious, there is no worm in the head, and the month of Safar is not unlucky. Allah has created every soul and has written down what will happen to it in its life and its sustenance."