Genesis 20:9-12

9Then Abimelech called Abraham and asked, “What have you done to us? How have I sinned against you, that you have brought such tremendous guilt upon me and my kingdom? You have done things to me that should not be done.” 10Abimelech also asked Abraham, “What prompted you to do such a thing?”

11Abraham replied, “I thought to myself, ‘Surely there is no fear of God in this place. They will kill me on account of my wife.’ 12Besides, she really is my sister, the daughter of my father—though not the daughter of my mother—and she became my wife.