Sahih Bukhari | Volume 7 | Hadith Number 608

Narrated by Abu Huraira
Allah's Apostle said, '(There is) no 'Adwa (no contagious disease is conveyed without Allah's permission) nor is there any bad omen (from birds), nor is there any Hamah, nor is there any bad omen in the month of Safar, and one should run away from the leper as one runs away from a lion."