When something works, why not go with it again? So must have thought Abraham as he sets up Abimelech for a little con job.
Bible Reading: Genesis 20
1: And Abraham journeyed from thence toward the south country, and dwelled between Kadesh and Shur, and sojourned in Gerar. 2: And Abraham said of Sarah his wife, She is my sister: and Abimelech king of Gerar sent, and took Sarah. 3: But God came to Abimelech in a dream by night, and said to him, Behold, thou art but a dead man, for the woman which thou hast taken; for she is a man's wife. 4: But Abimelech had not come near her: and he said, Lord, wilt thou slay also a righteous nation? 5: Said he not unto me, She is my sister? and she, even she herself said, He is my brother: in the integrity of my heart and innocency of my hands have I done this. 6: And God said unto him in a dream, Yea, I know that thou didst this in the integrity of thy heart; for I also withheld thee from sinning against me: therefore suffered I thee not to touch her. 7: Now therefore restore the man his wife; for he is a prophet, and he shall pray for thee, and thou shalt live: and if thou restore her not, know thou that thou shalt surely die, thou, and all that are thine. 8: Therefore Abimelech rose early in the morning, and called all his servants, and told all these things in their ears: and the men were sore afraid. 9: Then Abimelech called Abraham, and said unto him, What hast thou done unto us? and what have I offended thee, that thou hast brought on me and on my kingdom a great sin? thou hast done deeds unto me that ought not to be done. 10: And Abimelech said unto Abraham, What sawest thou, that thou hast done this thing? 11: And Abraham said, Because I thought, Surely the fear of God is not in this place; and they will slay me for my wife's sake. 12: And yet indeed she is my sister; she is the daughter of my father, but not the daughter of my mother; and she became my wife. 13: And it came to pass, when God caused me to wander from my father's house, that I said unto her, This is thy kindness which thou shalt shew unto me; at every place whither we shall come, say of me, He is my brother. 14: And Abimelech took sheep, and oxen, and menservants, and womenservants, and gave them unto Abraham, and restored him Sarah his wife. 15: And Abimelech said, Behold, my land is before thee: dwell where it pleaseth thee. 16: And unto Sarah he said, Behold, I have given thy brother a thousand pieces of silver: behold, he is to thee a covering of the eyes, unto all that are with thee, and with all other: thus she was reproved. 17: So Abraham prayed unto God: and God healed Abimelech, and his wife, and his maidservants; and they bare children. 18: For the LORD had fast closed up all the wombs of the house of Abimelech, because of Sarah Abraham's wife.
John's Midrash
This is not the first time that Abraham has utilized Sarah’s feminine charms in order to extract material favors from a wealthy man. In Genesis 12, we find Abram and his wife Sarai traveling in Egypt (they will not be renamed “Abraham” and “Sarah” by God until Genesis 17). Abram introduces Sarai as his “sister” to Pharoah, the King of Egypt. The duped Pharoah showers the two “siblings” with money, servants, and goods in order to get up close and personal with Sarai. Now in Genesis 20, they are traveling in the Kingdom of Gerar, and they run precisely the same confidence game on King Abimelech. So how do these two stories compare? In both cases, Abe misleadingly presents his wife as his sister. Abe argues that godless foreigners would surely kill him if they believed him to be Sarah’s husband, but that he would be safe if they believed him to be her brother. Likewise in both episodes, Abe and Sarah end up getting richly rewarded for lying about the true nature of their relationship. Now let us examine some differences. In the first story, God adds injury to insult by sending plagues upon the tricked Egyptian King. But in this second story, God actually shows a limited amount of sympathy for the duped king Abimelech. God gives Abimelech a chance to restore Sarah to Abraham and thus avoid the death penalty for taking another man’s wife. In the first story, Abraham doesn’t even bother to respond when Pharoah asks of him, “What is this that thou hast done unto me? Why didst thou not tell me that she was thy wife?” In this second story, Abimelech asks of Abe, “What hast thou done unto us? And what have I offended thee, that thou hast brought on me and on my kingdom a great sin?” This time Abe does deign to respond, but his answer reeks of equivocation and self justification. He tries to explain that in some technical sense, Sarah really can be considered his sister, so he wasn’t really lying after all. (Incidentally, for you Bible buffs who are also into American politics, this brings to mind our fellow Bible Studier Bill Clinton’s Grand Jury testimony and his classic line, “That depends on what the meaning of ‘is’ is.”) In neither story does God hold Abraham to account for what to our small human minds clearly seems like bad behavior. Why does God not punish Abraham at all for this repeated pattern of theft by deception? Well here is this man’s educated guess. In Genesis 17, at God’s request, 99 year old Abraham undergoes circumcision. Maybe, in God’s eyes, that was punishment enough for a lifetime of transgressions.