Musnad Ahmad

It is narrated from Hazrat Abu Huraira (may Allah be pleased with him) that the Holy Prophet (peace and blessings be upon him) said three times: No disease is contagious. A Bedouin said, "Then what about the camels who run around in the desert like deer, and suddenly a mangy camel joins them and makes all of them mangy?" The Holy Prophet (peace and blessings be upon him) remained silent for a while and then asked him, "Where did the first camel get the mange from?" No disease is contagious, the month of Safar is not unlucky, and there is no reality to a worm coming out of the skull. Allah has created every human being, and his life, death, calamity, and sustenance have all been written.