{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.

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     Gerar: marking the southern boundary of Canaan.

20:2     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.

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.

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

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.

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

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.

21:6     God has brought me laughter: “laughter” (Heb. yishaq) is repetition 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   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).

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

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

21:18   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.

21:20   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.

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 which Abraham dug (v.30).

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).

21:31   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 (oath of the agreement and Abraham’s offer of 7 ewes). Beersheba was a landmark at 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.