Shemot 15:26

And said, If thou wilt diligently pay heed to the voice of HASHEM Eloheicha, and will do that which is yashar in His sight, and will give ear to do His mitzvot, and be shomer over all His chok, I will put none of these machalah (diseases) upon thee, which I put upon the Egyptians; for Ani Adonoi rofecha (I am HASHEM that healeth thee).