Genesis 12:18
And Pharaoh called Abram, and said, What is this that thou hast done unto me? why didst thou not tell me that she was thy wife? And Pharaoh called Abram, and said, What is this that thou hast done unto me? why didst thou not tell me that she was thy wife?
The rebuke belongs to Abraham's further trial when severe famine in the land drove him down into Egypt. Pharaoh confronted Abram after discovering that Sarai was his wife, reproaching him for concealing the marriage and asking why he had not told him. The concealment had put Sarai in danger, since it could have led Pharaoh to take her as his wife.
The episode stands as a record of failure showing that even a man entrusted with great responsibilities can yield to temptation and sin. Yet God gave Abraham favor with the Egyptians, so that he left Egypt with more than he had when he entered. Through Abraham God was made known in Egypt, as his integrity and benevolence represented God among the surrounding peoples.
The account of this failure is preserved as a warning and lesson. Believers can rise again through God's grace, which encourages others to renew their struggle against sin.