Sermon notes December 7th, 2025

GENESIS 21

Isaac Is Born

This chapter begins with the fulfillment of promise, when the Lord visited Sarah. In this instance, God is visiting Sarah by mercifully delivering her from an apparent hopeless situation of infertility, as He had promised (Genesis 17:6). A year after God made this promise, Sarah conceived and bore a son. Despite Sarah and Abraham's old age, this was the appointed time by God for them to have a child. The birth was a miracle of God, because Abraham and Sarah were past childbearing age. Abraham was 75 years old when God first promised him a son, and he was 99 years old (and Sarah was 90) when this promise was restated years later (Genesis 17:1, Genesis 17:17).

• However, Isaac was born exactly when God said he would be. A year prior, God visited Abraham's camp and promised they would have a son. Sarah doubted the promise that she would have a child at her age, laughing (within herself). God responded to her, saying, "Is anything too difficult for the Lord? At the appointed time I will return to you, at this time next year, and Sarah you will have a son"               (Genesis 18:14).

Genesis 21:1-3                                               New King James Version

1   And the Lord visited Sarah as He had said, and the Lord did for Sarah as He had spoken. 

2   For Sarah conceived and bore Abraham a son in his old age, at the set time of which God had spoken to him. 

3   And Abraham called the name of his son who was born to him—whom Sarah bore to him—Isaac.

• Isaac: Originally, the name Isaac was meant as something of a rebuke of the laughter of Abraham and Sarah (Genesis 17:17-19 and 18:12-15), but God turned a gentle rebuke into an occasion for joy.

Isaac became a wonderful type and picture of the Messiah to come.       Jesus Christ comes some 2000 years later but see the similarities:

• Both were specially promised sons.
• Both conceptions were miraculous.
• Both were born after a period of delay.
• Both mothers were given assurance by the truth of God’s omnipotence (Genesis 18:13-14; Luke 1:34, 37).

(the quality of having unlimited or very great power "God's omnipotence")

• Both were given names rich with meaning before they were born.
• Both births occurred at God’s appointed time (Genesis 21:2; Galatians 4:4).
• Both births were accompanied by great joy (Genesis 21:6; Luke 1:46-47; 2:10-11).

Genesis 21:4-8

4   Then Abraham circumcised his son Isaac when he was eight days old, as God had commanded him. 

• It seems as Abraham is back, he’s all in now, he knows this God will do as he says.

5   Now Abraham was one hundred years old when his son Isaac was born to him. 

6   And Sarah said, “God has made me laugh, and all who hear will laugh with me.” 

7   She also said, “Who would have said to Abraham that Sarah would nurse children? For I have borne him a son in his old age.”

• Can you feel her joy? Yes, she laughed within herself, I think she knew God could do this, but would He? Considering their actions.

8   So the child grew and was weaned. And Abraham made a great feast on the same day that Isaac was weaned.

• Weaning a child in these days was somewhere between 2 and 5 years. These little things help to give us a timeline.

Genesis 21:9-13

9   And Sarah saw the son of Hagar the Egyptian, whom she had borne to Abraham, scoffing. 

• The KJV uses the word “mocking”.

10   Therefore she said to Abraham, “Cast out this bondwoman and her son; for the son of this bondwoman shall not be heir with my son, namely with Isaac.”  

• Ishmael would have been between fifteen and seventeen. When Sarah saw Ishmael mocking Isaac at the weaning party, she ordered Abraham to cast out Hagar and her son. Paul interprets this action as evidence that law persecutes grace, that law and grace cannot be mixed, and that spiritual blessings cannot be obtained on the legal principle (Gal. 4:29-31)

Galatians 4:29-31                                            New King James Version

29   But, as he who was born according to the flesh then persecuted him who was born according to the Spirit, even so it is now. 

30   Nevertheless what does the Scripture say? “Cast out the bondwoman and her son, for the son of the bondwoman shall not be heir with the son of the freewoman.” 

31   So then, brethren, we are not children of the bondwoman but of the free.

Genesis 21:11-16

11   And the matter was very displeasing in Abraham’s sight because of his son.

• I understand how Abraham feels. It sounds like Sarah is being harsh and unfair. That’s why I brought in Galatians 4. Sarah was speaking truth and sometimes the truth, yes, sets us free, but it can also be painful. 

12   But God said to Abraham, “Do not let it be displeasing in your sight because of the lad or because of your bondwoman. Whatever Sarah has said to you, listen to her voice; for in Isaac your seed shall be called. 

13   Yet I will also make a nation of the son of the bondwoman, because he is your seed.”

14   So Abraham rose early in the morning, and took bread and a skin of water; and putting it on her shoulder, he gave it and the boy to Hagar, and sent her away. Then she departed and wandered in the Wilderness of Beersheba. 

Wilderness of Beersheba holds a multifaceted role within the biblical narrative, serving as a physical and spiritual landscape where God's presence and provision are powerfully demonstrated. We all experience spiritually this desert place, where hope is lost.

• Perhaps Abraham did not want to give up Ishmael because he considered the son of Hagar something of a backup plan. If something should happen to Isaac, there would always be Ishmael. God did not want Abraham to trust in a backup son or in a backup plan. God wanted Abraham to trust in Him.
• Abraham might have been tempted to reject Sarah’s counsel just because it was Sarah who offered it. Instead, he sought the LORD in the matter, did what Sarah suggested, and did so apparently without feeling he merely gave in to Sarah’s demands.
• God’s solution was clear — get rid of the son of the flesh. There was to be no reconciliation with the flesh, no peaceful coexistence. The son of the flesh must simply be put away forever.
• The solution is the same in our own battle between trusting in the flesh and trusting in the Holy Spirit: cast out this bondwoman and her son. Law and grace cannot live together as principles for our Christian life, and there is no question we belong to the free, not the bondwoman.

15   And the water in the skin was used up, and she placed the boy under one of the shrubs. 

16   Then she went and sat down across from him at a distance of about a bowshot;( maybe a hundred yards) for she said to herself, “Let me not see the death of the boy.” So, she sat opposite him, and lifted her voice and wept.

• It may have seemed ruthless of Abraham to do this, but it was exactly what God wanted, and exactly what needed to happen.
• Flesh and blood do not make the strongest bond. God wants us to honor Him. There are circumstances where we can do nothing other than to put away family for the glory of God.
• God wants us to be ruthless with the flesh in the same manner: And those who are Christ’s have crucified the flesh with its passions and desires (Galatians 5:24).
• Took bread and a skin of water: Abraham was a wealthy man and could certainly afford to give them more supplies, even giving them a donkey or several pack animals. Yet Abraham realized that without God’s help, no matter what he gave them, it would not be enough. But with God, things would turn out all right.

Genesis 21:17-20

17   And God heard the voice of the lad. Then the angel of God called to Hagar out of heaven, and said to her, “What ails you, Hagar? Fear not, for God has heard the voice of the lad where he is. 

18   Arise, lift up the lad and hold him with your hand, for I will make him a great nation.”

• As Hagar and Ishmael traveled away from Abraham, their supplies eventually ran out. Their water was used up and Hagar left Ishmael under the shade of one of the shrubs, expecting their soon death in the wilderness.
• “Behold the compassion of a mother for her child expiring of thirst, and remember that such a compassion ought: “all Christians to feel towards souls that are perishing for lack of Christ”, perishing eternally, perishing without hope of salvation.” (Spurgeon)
• God heard the voice of the lad: As Hagar lifted her voice and wept, God answered. Curiously, God answered in response to the voice of the lad instead of specifically to Hagar’s weeping. In some way, Ishmael cried out for mercy and help.

19   Then God opened her eyes, and she saw a well of water. And she went and filled the skin with water, and gave the lad a drink. 

20   So God was with the lad; and he grew and dwelt in the wilderness, and became an archer. 

• Spurgeon explained the likeness between Hagar and the one who needs God. “As in Hagar’s case, the supply of their necessities is close at hand: the well is near. Secondly, it often happens that that supply is as much there as if it had been provided for them and for them only, as this well seemed to have been. And, thirdly, no great exertion is needed to procure from the supply already made by God all that we want. She filled her bottle with water — a joyful task to her; and she gave the lad drink.”
• So God was with the Ishmael: The idea is emphasized that God was not against Ishmael and his descendants. God was with Ishmael and had a promise for his future.

Genesis 21:21

21   He dwelt in the Wilderness of Paran; and his mother took a wife for him from the land of Egypt.

• Now there’s a change of the storyline here in this chapter, it moves from Isaac’ story back to Abraham’s dealing. It seems he’s changed and has become more confident in himself and in God.

Genesis 21:22-24

22   And it came to pass at that time that Abimelech and Phichol, the commander of his army, spoke to Abraham, saying, “God is with you in all that you do. 

• Abimelech did not notice this because of Abraham’s integrity; we have seen that. But the blessing is still evident in his life. Abraham had the greatest of all blessings: the presence of God in his life. Can people see the blessing in your life? “I think that the greatest blessing God ever gives to a man is His own presence. If I had my choice of all the blessings of this life, I certainly would not ask for wealth, for that can bring no ease; and I certainly would not ask for popularity, for there is no rest to the man in that. 

23   Now therefore, swear to me by God that you will not deal falsely with me, with my offspring, or with my posterity; but that according to the kindness that I have done to you, you will do to me and to the land in which you have dwelt.”

24  And Abraham said, “I will swear.”

Genesis 21:25-31

25   Then Abraham rebuked Abimelech because of a well of water which Abimelech’s servants had seized. 

• Because Canaan had no significant rivers and a great reliance upon rain, a well was an important and strategic property. Apparently, Abraham was in possession of a well of water that Abimelech’s servants had seized. The man of faith did not simply accept this wrong; he rebuked Abimelech because of a well.

26   And Abimelech said, “I do not know who has done this thing; you did not tell me, nor had I heard of it until today.” 

• We don’t know if this is the same Abimelech, because the name Abimelech was the title of a ruler among the Canaanites, not a specific name. But I think it’s the same guy. This ruler and Ph-i-chol, the commander of his army this is the first we see of him.

27   So Abraham took sheep and oxen and gave them to Abimelech, and the two of them made a covenant. 

• The sheep and oxen were probably used as sacrifices to make or cut the covenant, as in Genesis 15:7-21.

28   And Abraham set seven ewe lambs of the flock by themselves.

29   Then Abimelech asked Abraham, “What is the meaning of these seven ewe lambs which you have set by themselves?”

• The seven ewe lambs were special gifts from Abraham to Abimelech to show favor and offer some compensation for his loss of access to the well. Abraham understood his own property rights but was not greedy or miserly. The acceptance of the seven lambs was Abimelech’s recognition that Abraham had dug this well and it belonged to him.

30   And he said, “You will take these seven ewe lambs from my hand, that they may be my witness that I have dug this well.” 

31   Therefore he called that place Beersheba, because the two of them swore an oath there.

• This was a descriptive name. Beersheba means watering place, well of underground water. Some understand the Biblical name Beersheba as well of seven or well of the oath. 
• Beersheba would become a notable place in Israel’s continuing history and continues today as an important city in modern Israel (Beer-Sheva).

Genesis 21:32-34

32   Thus they made a covenant at Beersheba. So, Abimelech rose with Phichol, the commander of his army, and they returned to the land of the Philistines. 

33   Then Abraham planted a tamarisk tree in Beersheba, and there called on the name of the Lord, the Everlasting God. 

• After the successful treaty, Abraham did something that looked forward to coming decades and generations. A tamarisk tree takes a long time to grow, but Abraham knew God had promised the land to him and his descendants forever.

34 And Abraham stayed in the land of the Philistines for many days.

• Even through this time of conflict in his family and among his neighbors, Abraham kept a real, live walk with God. Conflict did not drive him away from God, but he allowed it to push him closer to the LORD.

The most likely resolution is that Scripture’s reference to “Philistines” in Abraham’s day does not contradict historical data. It aligns with common ancient practices of naming peoples and places by terms recognizable to subsequent audiences. Moreover, an earlier or related subset of the Philistines may indeed have been established in Canaan prior to the larger influx of Sea Peoples in the 12th century BC. Archaeological findings, ancient naming conventions, and textual analysis together support the credibility of Genesis’s account.