{7}         Birth of Isaac (Gen 20—21)


Part I. Abraham under the Covenant (17:1—21:34)

I3.    Abraham and Sarah in Gerar (20:1–18)

·         Abraham and Sarah lied once again about their relationship. This time the victim was Abimelech, the Philistine king. God appeared in Abimelech’s dream, demonstrating God’s grace in providing an opportunity to repent. Abimelech’s reversal contrasted with the unrepentent wicked Sodomites. The irony of the story is that Abraham brought both curse and blessing for the Philistines: curse for obtaining Sarah, resulting in a barren household, and blessing by the intercession of Abraham, bringing the healing of the court’s women.

I4.    Birth of Isaac (21:1–21)

·         The birth of Isaac created a rivalry to the right of inheritance. Eventually, Sarah persuaded Abraham to evict Hagar and Ishmael who then grew up in the desert.

I5.    Abraham’s treaty with Abimelech (21:22–34)

·         The Philistine king Abimelech initiated a non-aggression pact with Abraham and Abraham established Beersheba as his base.



20:1     He stayed: sojourned, not permanently. Lot as an alien was molested by the wicked Sodomites; Abraham as an alien encountered danger among the Philistines.

Gerar: marking the southern boundary of Canaan.

20:2     Abilmelech: the king of Philistines (Gen 21:32) at Gerar. The same name occurs in ch.26 when Isaac attempted the same deception (Gen 26:1). Although the name of the king (Abimelech) was the same, there were likely two different kings because it was at least 40 years later. So Abimelech might be the throne name for the Gerarites.

She is my sister: That Abraham repeated his wife-sister deception suggests that wife stealing was probably a common threat.

20:3     You are as good as dead: God announced his imminent death for taking Sarah. Since Abimelech did not challenge the morality of the charge, only his innocence of the crime, we may deduce that adultery among the Philistines was illegitimate.

20:4     had not gone near her: “gone near” in Hebrew describes illicit sexual relations. The king and his household had contracted a disease (v.17), probably a sexual disease.

Lord: The king appealed to the unspecified “Lord”, perhaps not knowing which of the gods of their polytheism had confronted him.

20:5     clear conscience and clean hands: innocent heart and not guilty behaviour. Why did God then punishment Abimelech if he was innocent? God used this to prevent sin from occurring. It should be remembered that the disease of Abimelech’s household was not permanent. The incident also made Abimelech respect Abraham and led to the later treaty.

20:6     I did not let you touch her: God’s action in preventing Abimelech from sinning, possibly because of the sexual disease.

20:7     he is a prophet: first occurrence of “prophet” in the Bible. Abraham was a prophet because of his mediatorial role, not the founder of the prophetic institution of Israel. He was the first in the Bible to intercede with God on behalf of others. Here, forgiveness was through restitution and intercession.

will die: Abimelech and his household suffered a fatal disease.

20:8     they were very much afraid: The Philistines might have heard about the destruction of Sodom.

20:9     great guilt: or great crime; adultery was regarded as a great crime in Near East ancient texts.

20:11   they will kill me because of my wife: Abraham’s defense consisted of 2 arguments: (1) he was afraid of being murdered.

20:12   she really is my sister: (2) Sarah was indeed his (half-)sister.

daughter of my father: could mean descendant of my ancestor.

20:14–16         Abimelech brought sheep and cattle: Abimelech paid 3 reparations: (1) animals and people, (2) offer of land, (3) silver—1000 shekels of silver was a very generous gift as 20 shekels could purchase a slave (Gen 37:28).

completely vindicated: The king’s payment declared Abraham and Sarah clear of culpability.

21:1     the LORD was gracious to Sarah: Hebrew word means “visited”. It is a common metaphor conveying the intervention of God.

21:2     God had promised him: God had fulfilled His promise, mentioned twice (v.1,2).

21:3     the name Isaac: meaning “he (child of the father) laughs, smiles”.

21:4     Abraham circumcised him: While God fulfilled His promise, Abraham obeyed God’s commands by naming his son Isaac and circumcised him on the 8th day.

21:5     100 years old: again emphsizing Abraham’s old age and God’s miracle.

21:6     God has brought me laughter: “laughter” and “will laugh” (Heb. yishaq) are repetitions of Isaac’s name.

21:8     held a great feast: normally held when the child was 2 to 3 years old. The festive banquet, however, turned into a hostile setting when Ismael mocked Isaac.

21:9     was mocking: The Hebrew word could have a variety of meanings. However, the word here usually conveys a harmful nuance and Sarah’s hostile reaction confirmed it. Ishmael possibly ridiculed the name of the toddler. Apostle Paul, referring to the incident, also portrayed harmful behaviour by using the word “persecuted” (Gal 4:29).

21:10   that slave woman's son: Sarah insisted that Ishmael’s maternal lineage disqualified his seniority in the question about inheritance.

Get rid: strongly worded demand, same word for evictions of Adam (Gen 3:24), Cain (Gen 4:14), and dispossession of Canaan’s population (Ex 23:29–30).

21:11   distressed Abraham greatly: Abraham’s love had blinded him to the inevitability of losing his eldest son.

21:13   into a nation: God quieted Abraham’s heart by repeating the promise of making Ishmael into a nation. Abraham trusted the assurance of God and provided only rations for Hagar and Ishmael at their eviction.

21:14   Early the next morning: Abraham responded to God immediately.

wandered in the desert: isolated, having no home for a refuge, but not getting lost.

21:16   a bowshot away: Hagar did not want to hear her son’s cries; but God heard his cries.

21:18   make him into a great nation: The promise fell short of the grander promise made to Abraham and his chosen line—eternal promise, inheriting the land, and blessing for all peoples.

21:19   opened her eyes: God supernaturally helped Hagar to see the well.

21:20   became an archer: The bow was a practical necessity in the desert for hunting and defending against hostilities, a life Ishmael would always know (Gen 16:12).

21:21   Desert of Paran: located between the southern boundary of Canaan and north of Sinai, close to Egypt. It was the area settled by Ishmael’s descendants. The picture of Ishmael as the rejected son was complete: he was the son of a slave woman, married to an Egyptian, lived outside normal social bounds, and was remembered for his hostilities.

21:22   the commander of his forces: Abimelech brought with him the commander of his forces to signal the potential hostilities that could result if a peaceful settlement failed. But the presence of the commander indirectly raised the stature of Abraham.

God is with you in everything you do: Abimelech admitted God’s favour toward Abraham through his dream experience and perhaps from Abraham’s growing prosperity.

21:23   not deal falsely: indirectly reminding Abraham about his previous falsehood and asking for a reciprocal treatment for his own kind treatment of Abraham.

21:25   complained to Abimelech: Since the king sought open relations, Abraham put the proposal to the test by charging the king’s servant of commandeering his well. The well was probably on the margins of Philistine control but Abraham dug it (v.30).

21:26   I don't know: The king replied by appealing to ignorance and he shifted some blame to Abraham who had not notified him. He implied also that if he had known of the problem, he would not have proposed the treaty (“today”).

21:27   brought sheep and cattle: Abraham initiated the covenanct ritual by submitting voluntarily sheep and cattle which probably were slain by both men (see Gen 15:10).

21:28   seven ewe lambs: Female lamb was common in tabernacle ritual. It was vital to propagating the herd and the generous number of 7 reflected the importance of the well for Abraham. They were used in a formal agreement regarding the well.

21:29   What is the meaning: The offer of lambs was exceptional as shown by Abimelech’s puzzlement. By accepting the animals as a “witness”, Abimelech would be accepting the version of Abraham’s account of events.

21:31   Beersheba: meaning “well of oath” (Heb. sebua) or “well of seven” (Heb. seba). The ambiguity of the word is useful to account for both facts. Beersheba is located in northern Negev (southland) and was a landmark for distinguishing the southern boundary of Israel in the formula “from Dan to Beersheba” (Jdg 20:1; 2Sa 17:11; 1Ki 4:27). The place is important as the major residence of the patriarchs (Gen 22:19; 26:33; 28:10; 46:1,5).

21:33   tamarisk tree: a tree of the sandy Negev, a deciduous tree with small leaves providing good shade. It held religious significance indicating reproductive fertility.

the Eternal God: (Heb. El Olam) reminding Abraham that God’s will for man and nations could not be hindered.



·         Abraham committed the same deception again, thus turning one sin into a pattern of sinful behaviour. This is Abraham’s weakness. Everyone faces certain temptations that are difficult to resist. These are the vulnerable spots in our spiritual armour.

·         After a visit by the angels and appearance of God one year earlier, Sarah finally cried out with surprise and joy at the birth of her son. Because of her doubt, worry, and fear, she had forfeited the peace she could have felt in God’s promise to her. The way to bring peace to a troubled heart is to focus on God’s promises.