Genesis 26:7-9

The men of the land noticed Rebekah’s beauty and asked Isaac about her. “Oh, she’s just my sister,” he replied. Rebekah was indeed very beautiful, and he was afraid to tell them, “She’s my wife,” for he thought that the men of the land would kill him and take his wife. One day, after Isaac had lived there awhile, the Philistine king Abimelech looked out his window and saw Isaac affectionately caressing his wife Rebekah. So Abimelech summoned Isaac and said, “So, this woman is your wife! Why did you say that she was your sister?” “Because I thought the men of the land would kill me and take her,” Isaac said.