Genesis 20:9-12

9Then Abimelech called Abraham and said to him, “What have you done to us? And how have I offended you that you have brought on me and my kingdom a great sin? You have done to me what ought not to be done [to anyone].”

10And Abimelech said to Abraham, “What have you encountered or seen [in us or our customs], that you have done this [unjust] thing?”

11Abraham said, “Because I thought, ‘Surely there is no fear or reverence of God in this place, and they will kill me because of my wife.’

12Besides, she actually is my [half] sister; she is the daughter of my father [Terah], but not of my mother; and she became my wife.