Genesis 12:10-13

Now there was a famine in the land, and Abram went down to Egypt to dwell there, for the famine was severe in the land. 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.”