Exodus 4:6-8

Young's Literal Translation

⁶ And Jehovah saith to him again, `Put in, I pray thee, thy hand into thy bosom;' and he putteth in his hand into his bosom, and he bringeth it out, and lo, his hand [is] leprous as snow;

⁷ and He saith, `Put back thy hand unto thy bosom;' and he putteth back his hand unto his bosom, and he bringeth it out from his bosom, and lo, it hath turned back as his flesh --

⁸ `-- and it hath come to pass, if they do not give credence to thee, and hearken not to the voice of the first sign, that they have given credence to the voice of the latter sign.