Genesis 12:13
Say, I pray thee, thou art my sister: that it may be well with me for thy sake; and my soul shall live because of thee. Say, I pray thee, thou art my sister: that it may be well with me for thy sake; and my soul shall live because of thee.
A severe famine in the land came as another trial for Abraham and caused him to move down into Egypt. God gave him favor with the Egyptians there, so that when he left Egypt he had more than he had when he went in. This saying belongs to that sojourn in Egypt, when his life and conduct were among the means through which God was revealed to the people around him.
It stands in the record of his sin and failure, showing that even one favored by God can be overcome by temptation and fall. That failing was recorded as a warning to later generations that even believers can fall. It was recorded also as encouragement that through God's grace those who struggled and fell can take heart and rise again, overcome, and keep pressing on.