Genesis 26:8-10

When Isaac had been there for some time, King Abimelech looked down from his window and saw Isaac and Rebecca making love. Abimelech sent for Isaac and said, “So she is your wife! Why did you say she was your sister?” He answered, “I thought I would be killed if I said she was my wife.” “What have you done to us?” Abimelech said. “One of my men might easily have slept with your wife, and you would have been responsible for our guilt.”