Genesis 26:7-9

Young's Literal Translation

⁷ and men of the place ask him of his wife, and he saith, `She [is] my sister:' for he hath been afraid to say, `My wife -- lest the men of the place kill me for Rebekah, for she [is] of good appearance.'

⁸ And it cometh to pass, when the days have been prolonged to him there, that Abimelech king of the Philistines looketh through the window, and seeth, and lo, Isaac is playing with Rebekah his wife.

⁹ And Abimelech calleth for Isaac, and saith, `Lo, she [is] surely thy wife; and how hast thou said, She [is] my sister?' and Isaac saith unto him, `Because I said, Lest I die for her.'