Exodus 10:27-29

Young's Literal Translation

²⁷ And Jehovah strengtheneth the heart of Pharaoh, and he hath not been willing to send them away;

²⁸ and Pharaoh saith to him, `Go from me, take heed to thyself, add not to see my face, for in the day thou seest my face thou diest;'

²⁹ and Moses saith, `Rightly hast thou spoken, I add not any more to see thy face.'