Genesis 12:11-13

11As he was about to enter Egypt, he said to his wife Sarai, “Look, I know that you are a beautiful woman, 12and when the Egyptians see you, they will say, ‘This is his wife.’ Then they will kill me but will let you live. 13Please say you are my sister, so that I will be treated well for your sake, and on account of you my life will be spared.”