Genesis 12:11-13

11When Abram came near to Egypt, he said to his wife Sarai, ‘Listen to me. I know that you are a very beautiful woman.

12When the Egyptians see you they will say, “This is Abram's wife.” Then they will kill me, but they will let you live.

13So tell them that you are my sister. Then they will do good things to me, because they want to please you. They will not kill me because they will think that you are my sister.’