It is not clear where "there" was. It probably refers to Mamre-Hebron, the last known home of Abraham. From "there," Abraham and Sarah moved to the area around Gerar. Its powerful king, Abimelech, took Sarah for his wife.
    Abimelech desired Sarah--strange, since according to Genesis 17:17 she was ninety years old. Remember, though, these seemingly contradictory points arise because of the combination of stories from different sources, and we may just have to accept the fact that certain inconsistencies like this remain unresolved in the final text.

    Characteristic of the Elohist, God does not appear directly, but communicates in dreams or visions. Also, this story contains a first for Genesis: in a dream God comes to Abimelech, a foreigner. This opens up an intriguing possibility that Israel's God could be in relationship with a foreigner, and that a righteous Gentile could exist.
    The question of Abimelech's guilt is thorny. He is guilty of wrong because he took someone else's wife, but he is innocent in so far as he was deceived by Abraham. On top of it, Abimelech never even touched Sarah. So why should he be found guilty?

    God came to Abimelech a second time in a dream and revealed that he had been working in Abimelech's life to prevent him from doing anything wrong. Is the Elohist telling us God providentially attends to the behavior even of non-Israelites?
    Note also the language used to describe Abraham. God calls him a prophet. This is the first time the label of "prophet" is used in the Hebrew Bible. The term here refers to someone who is able to intercede between God and other people. The Elohist source as a whole appears to be intimately associated with prophetic circles in the North, and so would naturally be interested in prophetic models and in tracing the prophetic calling to Israel's earliest history.

    Abimelech took the whole matter very seriously. He called together his servants and they talked about it. Then he turned the tables and blamed the situation on Abraham. Abraham really was the guilty one because he led Abimelech into trouble with his deception.

    The reason Abraham acted the way he did is now made clear. He was concerned that there was no "fear of God" in Gerar. In fact, Abimelech and his men seemed to have had a very healthy respect for God, confirmed by the way in which God came to Abimelech directly, warned him, and saved him from disaster. The story seems to suggest that Abraham had underestimated the moral character of these foreigners. Apparently, "fear of God," a big interest of the Elohist, was not found exclusively in Israel.

    Abimelech graciously gave gifts to Abraham to make a public acknowledgement of responsibility. Furthermore, he gave an open invitation to Abraham to settle anywhere he wanted to. Then Abraham interceded prophetically and Abimelech and his people were made whole again. Even though Abraham was the one at fault, curiously he is also the one who can remedy the situation. He is a prophet and hence is capable of mediating healing to Abimelech and his people.

    The account of the birth of Isaac (21:1-7) is amazingly brief given the tremendous buildup. We learn that Abraham was one hundred years old at his birth and Sarah was ninety. The child was named Isaac, "he laughs," to memorialize Sarah's incredulous response upon hearing that she would become pregnant in her old age. Conforming to covenant, Isaac was circumcised on the eighth day.

Sister-Wife. The motif of the patriarch claiming that his wife is his sister is also found in Genesis 12:10-20 and 26:6-11, both by the Yahwist. Having this particular motif in three separate stories is one of the supporting reasons for a multiple literary source theory of the Pentateuch.

¹⁴ Then Abimelech took sheep and oxen, and male and female slaves, and gave them to Abraham, and returned his wife Sarah to him. ¹⁵ And Abimelech said, "Now, my land is open to you; live where you want to." ¹⁶ To Sarah he said, "See, I have given your brother a thousand pieces of silver; it is your vindication in the eyes of all who are with you; and it proves to everyone that you are in the right." ¹⁷ Then Abraham prayed to Elohim; and Elohim healed Abimelech, and also healed his wife and female slaves so that they could bear children. ¹⁸ For YHWH had closed all the wombs of the house of Abimelech because of Sarah, Abraham's wife. (20:14-18)

¹¹ Abraham said, "I did it because I thought, 'There is no fear of Elohim at all in this place. They will kill me because of my wife. ¹² Besides, she is my sister anyway, the daughter of my father (though not the daughter of my mother), and she became my wife.' ¹³ When Elohim made me leave my father's house, I said to her, 'This is how you should show your loyalty to me: everywhere we go, say of me, 'He is my brother.'" (20:11-13)

⁸ So Abimelech rose early in the morning, and called all his servants, and told them everything; and the men were very afraid. ⁹ Then Abimelech called Abraham, and said to him, "What did you do to us? What did I do to you, that you should bring on me and my kingdom this problem? You did things to me that shouldn't have been done." ¹⁰ Abimelech also said to Abraham, "What were you thinking when you did this thing?" (20:8-10)

⁶ Elohim said to him in the dream, "I, too, know that you did this with a pure heart. It was I that kept you from sinning against me; for that reason I did not let you touch her. ⁷ Now then, return the man's wife. He is a prophet, he will pray for you, and you will live. But if you do not return her, you should know that you will die, you, and everything that belongs to you." (20:6-7)

³ Elohim came to Abimelech in a dream at night and said to him, "You are a dead man on account of the woman you have taken. She is married." ⁴ Now, Abimelech had not made any sexual advances. He said, "My Lord, would you kill people even though they were innocent?" ⁵ Did he not say to me, 'She is my sister'? And she is the one who said, 'He is my brother.' With a pure heart and clean hands I did this." (20:3-5)

¹ Abraham traveled from there to the area of the Negev and made his home between Kadesh and Shur. When he was staying in Gerar ² Abraham claimed about his wife Sarah, "She is my sister." So Abimelech, king of Gerar, had someone get Sarah. (20:1-2)