Genesis 20:7, commentary and pictures

God told Abimelech to give Sarah back to her husband, for Abraham was a prophet whose prayer would save his life, while keeping her would bring literal death on him and all his household.
Abraham had called his wife his sister a second time from fear and want of trusting faith, showing that even the father of believers had not yet come to perfection of faith.
Taking another man's wife was already known as a great sin bringing guilt on the taker and his kingdom, and though Abimelech had acted in integrity because he had been deceived, God kept him from touching her and warned him that to keep her would still bring punishable guilt.
The episode proves the law against adultery was known, binding, and in force long before Sinai, and that men were held accountable as transgressors of a known law even without a recorded express prohibition.
Abraham was a trusted servant of God endowed with the spirit of prophecy and close access to heaven, whose powerful intercession for another shows he stood approved before God.

Context and Wording

Genesis 20:7 belongs to Abraham's sojourn among the Philistines, when for the second time he said Sarah was his sister rather than his wife. The act came from fear and lack of truthfulness before Abimelech, and from want of trusting faith in God's protecting care. Even the father of believers showed unbelief in passing Sarah off as his sister and did not always trust God. He had not yet come to fullness of faith or to perfection of faith, but needed the lesson over and over. The wider account to which the verse belongs, including Abraham and Hagar, illustrates that his attempt to bring about God's promise through human planning was not God's plan and led to trouble and bondage.

The episode displays God's overruling providence in Abraham's sojourn and trials of faith. It belongs to God's providential dealings with the family of Abraham as the chosen progenitor of the Seed. It is part of the history of beginnings and the story of God's dealing with the Seed and the attempts of the enemy to thwart God's plan. There God's law was in force and gospel promises and prophecies made to His chosen shine. That setting presses readers whether they are children of Abraham.

Abimelech knew the true God, and his people showed a higher regard for morality than other nations of Palestine. God used him to administer a stern rebuke to Abraham. He sent Sarah back to Abraham and showed goodwill toward Abraham's household with gifts.

The verse commands Abimelech to restore Sarah to Abraham. It calls Abraham a prophet whose prayer would bring life and preserve Abimelech. It warns that refusal to restore her would bring death upon Abimelech and all that were his, including his household. The phrase thou shalt surely die means literal death, not spiritual death, consistent with its use elsewhere in the Bible.

Law Known Before Sinai

Taking another man's wife was already known to be a great sin bringing guilt upon the taker and his kingdom, and Abimelech himself acknowledged that wrong and guilt. God prevented Abimelech from touching Sarah and kept him from doing so, withholding the king from sinning against God by taking her. Taking her was sin against God, recognized as such before he touched her.

Abimelech had acted in integrity of heart and innocency of hands, with an honest heart and clean hands, because Abraham had said she was his sister. God directly instructed Abimelech not to keep another man's wife and warned him against transgressing His law in keeping her. Yet taking her would still have brought dire, punishable guilt and punishment upon him even though he had done it unwittingly.

The episode proves that the prohibition of adultery and the principle of the seventh commandment against adultery were known, binding, and in force in the patriarchal age and in Abraham's time long before the law was proclaimed at Sinai. God required Abimelech to restore Sarah to Abraham, warning that otherwise Abimelech and his household would die, and promised that Abraham as prophet would pray and preserve Abimelech's life. Knowledge of sin and of right and wrong was general before the law was given to Israel, men were held accountable as transgressors of a known law, and the early patriarchs understood the principle and were treated as guilty and punishable by God for violating it. The absence of a recorded express divine prohibition of adultery does not prove absence of obligation, just as with murder, idolatry, stealing, and the Sabbath, and the moral law and Ten Commandments are reflected in events recorded in Genesis as the rule of life.

The same account also demonstrates violation of the tenth commandment, in that Abimelech coveted Abraham's wife, showing that commandment was known and its violation recognized before Sinai. The same account is also cited as an example of violating the command against false witness. God spoke directly to Abimelech king of Gerar concerning Abraham's wife after Abraham had been called into the land of Canaan. This shows God continued after the fall to communicate in person and manifest His will to men, to the wicked as well as to the righteous, so that knowledge of God was kept alive among the nations.

Prophet and Intercessor

Abraham is named a prophet in the command to restore Sarah, marking him as a trusted servant of God. He was endowed with the spirit of prophecy. His close acquaintance with God gave him access to the King of heaven.

His prophetic standing is seen in that God revealed to him the coming judgment on Sodom before destroying the city. The same gift enabled him to know that the Canaanites would eventually be destroyed because of their wickedness.

As prophet he could pray for another person, standing as a powerful intercessor. God's assurance that his prayer would bring Abimelech life and preserve him shows he was approved by God, contrary to the charge that he was a liar.