Genesis 26:8-10

It came about, when he had been there a long time, that Abimelech king of the Philistines looked out through a window, and saw, and behold, Isaac was caressing his wife Rebekah. Then Abimelech called Isaac and said, “Behold, certainly she is your wife! How then did you say, ‘She is my sister’?” And Isaac said to him, “Because I said, ‘I might die on account of her.’ ” Abimelech said, “What is this you have done to us? One of the people might easily have lain with your wife, and you would have brought guilt upon us.”