Genesis 20:9-12

9Then Abimelech called to Abraham and said to him, “What have you done to us, and how have I sinned against you, that you brought great sin upon me and my kingdom? You’ve done to me things that should not be done!”

10Abimelech also said to Abraham, “What motivated you to do this thing?”

11Abraham said, “Because I thought, ‘There is certainly no fear of God in this place, so they’ll kill me, because of my wife.’

12And besides, she really is my sister. She’s my father’s daughter, though not my mother’s daughter. Then she became my wife.