Genesis 12:11-13

And it came to pass, when he was close to entering Egypt, that he said to Sarai his wife, “Indeed I know that you are a woman of beautiful countenance. Therefore it will happen, when the Egyptians see you, that they will say, ‘This is his wife’; and they will kill me, but they will let you live. Please say you are my sister, that it may be well with me for your sake, and that I may live because of you.”