Abraham's actions in Genesis 20 put Sarah and the promised covenant line at risk, a moment that Les Feldick frames as Satan's attack on the nation that would come from God's covenant with Abraham.
The biblical account records Abraham telling Abimelech that Sarah was his sister, causing Abimelech to take her. Les introduces the chapter by noting that Abraham is in his 99th year and that Ishmael is already 13, and in his broader teaching he shows that after God's covenant with Abraham, Satan turned against the nation that would come from that agreement.
Genesis 20:2 — This verse records Abraham's action of identifying Sarah as his sister, which leads directly to the crisis of the chapter.
Genesis 20 records that Abraham sojourned in Gerar and said of Sarah his wife, "She is my sister." Abimelech king of Gerar then sent and took Sarah. God came to Abimelech in a dream and told him he was a dead man because the woman he had taken was a man's wife. Abimelech protested that he had acted with integrity, and God acknowledged that He had kept him from touching Sarah. When Abraham was questioned, he explained that he thought there was no fear of God in that place and that he would be killed for Sarah's sake. He also said she was indeed his half-sister, so his statement was a half-truth. At the end of the chapter, Abraham prayed for Abimelech, and God healed Abimelech and his household so that the women could bear children again after God had closed their wombs because of Sarah.
Les begins his study of chapter 20 by emphasizing the timing: Abraham is in his 99th year, and Ishmael has already been born and is 13 years old. He also notes how the descendants of Abraham's relatives become the enemies of Israel. In a wider teaching on this period, Les points out that when Abraham came on the scene and God made the covenant with him, Satan immediately turned on that little nation that was going to come out of that covenant agreement "like no other group of people on earth." This places the Genesis 20 events squarely in the middle of Satan's opposition to the promised Redeemer. Les also shows what kind of man Abraham was—called by grace out of an idolatrous family, yet a man of faith who took God at his word. He also reminds his students that God said of Abraham, "I know him, that he will command his children and his household after him," showing the role Abraham was to play in the covenant line.
Genesis 20 shows that Abraham told Abimelech that Sarah was his sister. When questioned, 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." He also revealed that Sarah was the daughter of his father, though not of his mother, so she was indeed his sister and also his wife.
Les teaches that as soon as God brought Adam and Eve out of the garden and promised that the seed of the woman would bring the Redeemer, Satan immediately put in gear everything at his disposal to stop the Redeemer's coming. He first brought death to Abel, who was in that line, and then when Abraham arrived and God made the covenant with him, Satan turned on the nation that would come out of that covenant agreement.
Les explains that Abraham's family was steeped in idolatry in Ur of the Chaldees, which is why God told him to leave his family and his country. Against this backdrop, God in grace reached down to one man and called him out, and Abraham took God at His word. God promised that out of Abraham would come a nation, the nation of Israel.
The Timing of Genesis 20
Les introduces Genesis 20 by noting that Abraham is in his 99th year and that Ishmael, already born, is 13 years old.
Satan's Attack on the Covenant Nation
Les teaches that after God made the covenant with Abraham, Satan turned on the nation that would come from that covenant agreement.
Why God Chose Abraham
Les reads God's statement that He knew Abraham would command his children and household after him, showing Abraham's role in the covenant line.
Abraham's Faith Response
Les describes how God spoke directly to Abraham and how Abraham simply took God at His word.
Called Out of Idolatry
Les shows that Abraham's family was idolatrous and that God reached down to one man by grace.
Abraham's Pagan Background
Les notes that Terah and Abraham's relatives served other gods, so Abraham came out of an idolatrous environment.
The Call of Abraham
Les emphasizes that Abraham was a man of faith who took God at His word when he was told to leave his country.
The Promise of a Nation
Les explains that God called Abraham out of the mainstream of humanity and promised that out of him would come the nation of Israel.
Genesis 20:2: And Abraham said of Sarah his wife, She is my sister: and Abimelech king of Gerar sent, and took Sarah.
Abraham's words to Abimelech are the action at the center of the Genesis 20 account.
Genesis 20:11: 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.
Abraham explains that fear for his life led him to say Sarah was his sister.
Genesis 20:12: 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.
Abraham reveals the half-truth that Sarah was his half-sister.
Genesis 20:17: So Abraham prayed unto God: and God healed Abimelech, and his wife, and his maidservants; and they bare children.
Abraham's prayer brings healing to Abimelech's household, ending the episode.
Genesis 12:1-3: Now the LORD had said unto Abram, Get thee out of thy country, and from thy kindred, and from thy father's house, unto a land that I will shew thee: And I will make of thee a great nation, and I will bless thee, and make thy name great; and thou shalt be a blessing: And I will bless them that bless thee, and curse him that curseth thee: and in thee shall all families of the earth be blessed.
God's original call and promise to Abraham, which Genesis 20 threatens.
Genesis 17:1: And when Abram was ninety years old and nine, the LORD appeared to Abram, and said unto him, I am the Almighty God; walk before me, and be thou perfect.
This records that Abraham was 99 years old when God reaffirmed the covenant, the same age Les notes in Genesis 20.
Genesis 17:25: And Ishmael his son was thirteen years old, when he was circumcised in the flesh of his foreskin.
This records Ishmael's age of 13 when Abraham's household was circumcised.
Genesis 18:19: For I know him, that he will command his children and his household after him, and they shall keep the way of the LORD, to do justice and judgment; that the LORD may bring upon Abraham that which he hath spoken of him.
God's testimony about Abraham's future faithfulness as head of his household.
Abraham told Abimelech that Sarah was his sister. When questioned, Abraham explained that she was indeed the daughter of his father though not of his mother, so she was his half-sister and wife. God still treated Abraham's deception seriously and warned Abimelech that Sarah was a man's wife.
God told Abimelech that he was a dead man because of the woman he had taken, for she was a man's wife. God also said that Abraham was a prophet and would pray for Abimelech, and that Abimelech must restore Sarah to Abraham.
Les Feldick points out that Abraham was in his 99th year and Ishmael was already 13 when Genesis 20 opens. This timing matters because the covenant son through Sarah had not yet arrived, and the covenant line was still vulnerable.
Watch the Teaching: Abraham, Sarah, and the Allegory of Law vs. Grace | Genesis 20-21