Genesis 26:8-11

8And it came to pass, when he had been there a long time, that Abimelech king of the Philistines looked out at a window, and saw, and, behold, Isaac was sporting with Rebekah his wife. 9And Abimelech called Isaac, and said, Behold, of a surety she is thy wife: and how saidst thou, She is my sister? And Isaac said unto him, Because I said, Lest I die because of her. 10And Abimelech said, What is this thou hast done unto us? one of the people might easily have lain with thy wife, and thou wouldest have brought guiltiness upon us. 11And Abimelech charged all the people, saying, He that toucheth this man or his wife shall surely be put to death.