Genesis 21 - Abraham and Isaac

Table of Contents



  1. The orange arrow from Gerar (box 6) towards Egypt marks the expulsion of Ishmael and Hagar into the wilderness of Beersheba

  2. Separation was necessary to protect the son of the promise

  3. The red arrow from Beersheba to Jerusalem (box 7) denotes the path to and from the offering of Isaac.

  4. Map credit1

Genesis 21 and Romans, Galatians, and Hebrews

  • An understanding of Genesis 21 is paramount to understanding Paul’s/Hebrew’s arguments.

  • Romans, Galatians, and Hebrews and only these three New Testament books discuss Genesis 21.

    • Acts references the birth of Isaac; James and Hebrews reference the sacrifice of Isaac in Genesis 22.
  • It is easy to read Galatians and come away that Paul was somehow anti-law or anti-Judaism.

    • This train of thought is deeply flawed and runs the risk of missing Paul’s points entirely.

    • He is focused not on Judaism as a whole, but on the Messiah-rejecting Jews who are knowingly or unknowingly continuing in legalism instead of accepting the free gift the Messiah brings.

  • As an aside, the three books, and only these three New Testament books quote Habakkuk 2:4 (KJV) “but the just shall live by his faith.”

  • Romans, Galatians, and Hebrews seem to form a trilogy on Habakkuk 2:4.

    • Theme of Romans: who are the justified?

    • Theme of Galatians: how shall the justified live?

    • Theme of Hebrews: faith in the promises.

  • This leads many to suspect Paul is the author of Hebrews. If he did not, this is an even greater miracle, because whoever wrote Hebrews unknowingly completed the trilogy!

Genesis 21:1-3

Then the LORD took note of Sarah as He had said, and the LORD did for Sarah as He had promised. So Sarah conceived and bore a son to Abraham in his old age, at the appointed time of which God had spoken to him. Abraham named his son who was born to him, the son whom Sarah bore to him, Isaac.

  • Galatians 4:23 But the son by the slave woman was born according to the flesh, and the son by the free woman through the promise.

  • Hebrews 11:11 By faith even Sarah herself received the ability to conceive, even beyond the proper time of life, since she considered Him faithful who had promised.

  • Other translations say “God remembered Sarah.”

    • This is not that God forgot, but that He remembered His promise.
  • “Appointed time” = mo’ed. The Jewish festivals are Moedim. Shabbat is a moed. A moed is a big deal.

    • Perhaps Isaac was born on a festival day, just as some speculate Jesus might have been born on Yom Kippur or the first day of Tabernacles.

      • Either day fits – He is our atonement and he dwells/tabernacles among us.
    • “The Bible uses a miraculous birth to indicate that God has set aside that child for some great purpose.” (SOM 94)

  • Yitzhak is related to the Hebrew verb צחק, which means to laugh, but often carries a nuanced connotation of mocking/scorning or even sexual play.

    • We’ll unpack more at verse 9.

Genesis 21:4-7

Then Abraham circumcised his son Isaac when he was eight days old, as God had commanded him. Now Abraham was a hundred years old when his son Isaac was born to him. Sarah said, “God has made laughter for me; everyone who hears will laugh with me.” And she said, “Who would have said to Abraham that Sarah would nurse children? Yet I have given birth to a son in his old age.”

  • Practically, in an age of high infant mortality rates, eight days, an infant was considered viable.

    • Isaac was circumcised according to the letter of the law on the 8th day.

    • This is contrasted with Ishmael, who was circumcised at age 13; he was still circumcised, but in a typological sense, not when he “should” have been according to the Law.

  • Given the nuanced meaning of Tzahaq, this may not necessarily be laughing in joy, but laughing in amazement. Sarah and Abraham both laughed in disbelief and perhaps mockery.

  • Isaac’s birth was a true miracle.

    • There is an overarching theme in the Bible of God miraculously opening a closed womb. This extends to Mary; although she was not barren in the traditional sense, her womb was miraculously opened.

    • God made EVERYTHING in Sarah come to life – she didn’t just give birth but was able to nurse for a couple of years after.

Genesis 21:8-10

And the child grew and was weaned, and Abraham held a great feast on the day that Isaac was weaned. Now Sarah saw the son of Hagar the Egyptian, whom she had borne to Abraham, mocking Isaac. Therefore she said to Abraham, “Drive out this slave woman and her son, for the son of this slave woman shall not be an heir with my son Isaac!”

  • This episode becomes symbolic of the affliction of the Hebrew/Jewish people throughout the ages.

    • Galatians 4:29 But as at that time the son who was born according to the flesh persecuted the one who was born according to the Spirit, so it is even now.

    • Galatians 4:31 So then, brothers and sisters, we are not children of a slave woman, but of the free woman.

    • According to some reckonings, the 400 years of suffering and affliction culminating in the exodus from Egypt begins with this affliction of Isaac.

  • We don’t have much background on any tradition of a weaning feast.

  • We know who Hagar is, but the Narrator wants us to remember her as “Hagar the Egyptian.”

  • What did Ishmael do that was so bad that he and his mother had to be driven out?

    • Here’s this word Tzahaq again, translated as mocking.

    • “Laughter can be used for good or for ill.”2

    • Genesis 26:8 Now it came about, when he had been there a long time, that Abimelech king of the Philistines looked down through a window, and saw them, and behold, Isaac was caressing his wife Rebekah.

      • Caressing = sporting = “Tzahaqing”
    • Ishmael ridiculing and poking fun at his younger brother probably wouldn’t have led to the banishment.

    • Ishmael was quite possibly a sexual predator.

    • Sarah refuses to speak his name. Whatever it was, it had to be bad.

Walking In His Dust Along The Talmidim Way

Talmidim must drive out fleshly works and sin from our lives.

1 Corinthians 5:7 Clean out the old leaven so that you may be a new lump, just as you are in fact unleavened. For Christ our Passover also has been sacrificed.

  • Another theme in the Bible is the firstborn son doing something to forfeit his inheritance.

    • Normally, the firstborn son receives a double portion of the father’s estate.

    • If the son does something wicked, he forfeits his promise; then the next in line receives.

    • Not Ishmael but Isaac.

    • Not Esau but Jacob.

    • Not Reuben (and not Simeon or Levi) but Judah.

      • Here we have an especially odd situation. Joseph was the firstborn of Jacob’s favorite wife Rebekkah.

      • Judah receives the official double portion, but Joseph also receives a double portion with Ephraim and Manaesseh being adopted by Jacob.

Genesis 21:11-13

The matter distressed Abraham greatly because of his son Ishmael. But God said to Abraham, “Do not be distressed because of the boy and your slave woman; whatever Sarah tells you, listen to her, for through Isaac your descendants shall be named. “And of the son of the slave woman I will make a nation also, because he is your descendant.”

  • Galatians 4:28 And you, brothers and sisters, like Isaac, are children of promise.

  • Romans 9:7 nor are they all children because they are Abraham’s descendants, but: “THROUGH ISAAC YOUR DESCENDANTS SHALL BE NAMED.”

  • Hebrews 11:18 it was he to whom it was said, “THROUGH ISAAC YOUR DESCENDANTS SHALL BE NAMED.”

  • The banishment of Ishmael is Abraham’s 9th test.

    • We see here that he was reluctant and was “distressed.”

    • He loved Ishmael.

    • His specific tests:

      • Did he trust God to take care of him?

      • Did he trust God’s promises to make Ismael a great nation?

      • Did he trust Sarah’s judgment after the last time?

    • The trial of Ishmael prepared him for the final test in Genesis 22.

  • God had previously promised a great future for Ishmael, but Isaac is the one who will inherit.

  • It’s curious that the Narrator added, “whatever Sarah tells you, listen to her…”. Certainly, this was not the case in Genesis 16 or Genesis 3.

    • Genesis 3:17 Then to Adam He said, “Because you have listened to the voice of your wife, and have eaten from the tree about which I commanded you, saying, ‘You shall not eat from it’; Cursed is the ground because of you; With hard labor you shall eat from it All the days of your life.

Genesis 21:14-16

So Abraham got up early in the morning and took bread and a skin of water, and gave them to Hagar, putting them on her shoulder, and gave her the boy, and sent her away. And she departed and wandered about in the wilderness of Beersheba. When the water in the skin was used up, she left the boy under one of the bushes. Then she went and sat down opposite him, about a bowshot away, for she said, “May I not see the boy die!” And she sat opposite him, and raised her voice and wept.

  • Galatians 4:24 This is speaking allegorically, for these women are two covenants: one coming from Mount Sinai giving birth to children who are to be slaves; she is Hagar.

  • Galatians 4:31 So then, brothers and sisters, we are not children of a slave woman, but of the free woman.

    • Stern makes an interesting comment at Galatians 4:24, “Nowhere does the account in Genesis denigrate Hagar, hense there is no reason to demean the Mosaic Law on the basis of this passage.

    • It’s not the Torah or Judaism, but people who have perverted the Torah and Judaism into a legalistic system, which is equivalent to a return to slavery in Egypt.

  • This is essentially the same territory where she wandered in chapter 16.

  • We learned in Israel that in Abraham’s day, towns were generally situated about a day’s journey apart.

    • He outfitted her with one day’s provisions with the expectation that she would “refuel” at the next town, perhaps Beersheba 15 miles from Gerar.

    • For whatever reason, she doesn’t make it and heads into the wilderness/desert south of Beersheba.

      • Did she make it but was turned away because of her “status”?

      • Could she not make it that far?

      • Perhaps distressed, did she meander aimlessly?

Genesis 21:17-19

God heard the boy crying; and the angel of God called to Hagar from heaven and said to her, “What is the matter with you, Hagar? Do not fear, for God has heard the voice of the boy where he is. “Get up, lift up the boy, and hold him by the hand, for I will make a great nation of him.” Then God opened her eyes, and she saw a well of water; and she went and filled the skin with water and gave the boy a drink.

  • Another significant well moment.

  • Just as in chapter 16, God again sees Hagar and provides materially.

  • He also reiterates His promises that Hagar had forgotten.

  • The well was there; she just couldn’t see it. That’s a picture of us some days. We can’t open our eyes enough to see the blessing before us.

  • Through Romans and Galatians, many of us have a dim view of Hagar and Ishmael – certainly, some of this is deserved and as biblical types, they represent the things that we are supposed to reject.

  • But let’s remember the Bible’s worst sinners are pictures of you and me.

  • Ishmael messed up “bigly.” We mess up too.

  • Here God reaches out and offers both Hagar and Ishmael His mercy and protection. We can be critical because it doesn’t appear that this mercy had any lasting effect. One would have hoped that they could have followed the God of Abraham. We have the same choices when God shows us mercy. How often does God bail us out or see us through a tough spot only to have us forget about God a few moments later?

Walking In His Dust Along The Talmidim Way

When things seem hopeless, talmidim look for God’s promises.

Sometimes life hits us and we lose focus. When things seem bleak and we despair, we may need to open our eyes to the goodness of God.

1 Peter 3:14-15 But even if you should suffer for righteousness' sake, you will be blessed. Have no fear of them, nor be troubled, but in your hearts honor Christ the Lord as holy, always being prepared to make a defense to anyone who asks you for a reason for the hope that is in you; yet do it with gentleness and respect.

Genesis 21:20-21

And God was with the boy, and he grew; and he lived in the wilderness and became an archer. He lived in the wilderness of Paran, and his mother took a wife for him from the land of Egypt.

  • Paran is in the northeastern Sinai desert.

  • This region figures prominently in the Wilderness wanderings (specifically Numbers 13, where Kadesh-Barnea is located).

Genesis 21:22-24

At that time Abimelech and Phicol the commander of his army said to Abraham, “God is with you in all that you do. Now therefore swear to me here by God that you will not deal falsely with me or with my descendants or with my posterity, but as I have dealt kindly with you, so you will deal with me and with the land where you have sojourned.” And Abraham said, “I will swear.”

  • What a great testimony. I hope it can someday be said of me “God is with you in all that you do.”

    • Of course, God is with me in all that I do; but I don’t always live my life in a way that others recognize it.
  • Despite Abraham’s duplicity, his relationship with Abimelech blossoms into a fruitful and symbiotic partnership.

  • Oaths are legally binding – this is more than a handshake agreement between friends.

Genesis 21:25

When Abraham reproved Abimelech about a well of water that Abimelech’s servants had seized, Abimelech said, “I do not know who has done this thing; you did not tell me, and I have not heard of it until today.”

  • As part of a contract, one party has the right to notify the other if there is a potential material breach. Abraham is doing that here.

  • Beersheba is at the northern edge of the Negev desert. Even today, south of Beersheba is sparsely populated.

  • There is not much water, so what little water there is becomes a hot commodity.

  • Our tour guide’s wife is a hydrologist for the nation of Israel – even today, providing enough water for the population is of paramount interest. In the last ten years, the primary water source has shifted from the Jordan River and the Sea of Galilee to desalinated seawater from the Mediterranean.

In His Dust Talmidim Way Insight

When you reprove someone who has wronged you, have the good in mind.3

  • We can learn from Abraham’s admonishment.

    • Abraham was not angry, nor seeking to get even.

    • He confronted Abimelech with the goal of restoring their relationship; a relationship Abimelech didn’t even know was injured.

    • The challenge of a leader is that you can’t know everything, but it’s your job to know everything.

  • Abraham is reminding Abimelech that it was his job to know that his men were behaving dishonestly.

Matthew 18:15 “Now if your brother sins, go and show him his fault in private; if he listens to you, you have gained your brother.”

  • If you’re going to rebuke someone; do it one on one and ideally in person; not on social media.

  • Perhaps an associated insight is we need to receive bad news as an improvement opportunity.

    • We can take the position that Abraham’s goal was not to tattle but to build Abimelech up as a leader. This is of course in addition to remedying the immediate situation.

    • A senior executive I worked with paraphrased the famous line from the Godfather, “I want to hear good news right away and bad news immediately.”4

    • Fostering that kind of culture in an organization takes time but it is critical in our families and ministries as well as our businesses.

    • Even if the other person is not bringing the criticism forward in a spirit of edification, if the substance of the criticism has merit, we can still learn from it.

Revelation 3:19 ‘Those whom I love, I rebuke and discipline; therefore be zealous and repent.’

Genesis 21:27-28

So Abraham took sheep and oxen and gave them to Abimelech, and the two men made a covenant. Abraham set seven ewe lambs of the flock apart.

  • Other than when it involves Sarah, Abraham is highly skilled as a negotiator and at resolving conflict.

    • I take comfort in this – I was generally successful as a business executive and viewed as a capable and effective leader; yet I often struggle with leading my own family.
  • Sheva literally means “seven”; because of this episode, it also comes to mean “oath.”

Genesis 21:29-31

And Abimelech said to Abraham, “What is the meaning of these seven ewe lambs that you have set apart?” He said, “These seven ewe lambs you will take from my hand, that this may be a witness for me that I dug this well.” Therefore that place was called Beersheba, because there both of them swore an oath.

  • Wells turnout to be extremely significant in scripture. In John 4, Jacob’s well plays a prominent supporting role in the story of Jesus and the Samaritan woman.

  • Beersheba means literally “well of the seven” but denotatively, “well of the oath.”

Genesis 21:32

So they made a covenant at Beersheba. Then Abimelech and Phicol the commander of his army rose up and returned to the land of the Philistines.

  • This is a bit anachronistic as there were not yet Philistines in the coastal plain areas. Egyptians and Canaanites, yes; Philistines, no.

  • The narrator clarifies the geographic location for a later audience.

  • The first mention of the Philistines in history is around 1180 BC; we believe Abraham lived around 2000 or 1900 BC.

  • It’s similar to referring to “native Americans” who were around these lands long before the term “America” was used as a geographic label.

Genesis 21:33-34

Abraham planted a tamarisk tree in Beersheba and called there on the name of the LORD, the Everlasting God. And Abraham sojourned many days in the land of the Philistines.

  • The tamarisk is a good tree for the desert. It grows in sandy soil and provides ample shade and food for herbivores.

  • In Israel, we learned that “conquering the land” is not always a military campaign.

    • Planting trees, literal and figurative roots in the land, is another way Abraham conquered the land.

    • As the Zionists started to move back around the turn of the 20th century, much of the northern part of the country was a swamp. They imported Eucalyptus trees from Australia which sucked up all the water. The land is fertile once again.

    • Today, Israel boasts that it plants more trees than it harvests.

  • Everlasting in Hebrew is “olam”; it can also mean “world” or “universe”.

    • Almost all Jewish blessings start with “Baruch ata Adonai Eloheinu, Melech haOlam,” Blessed are you Lord our God, King of the Universe.”
  • Whenever we have tension and conflict, we should certainly seek God’s council for relief and godly wisdom on handling the situation.

    • Just don’t forget to call on His name after He delivers you from the test.

Pliskin, Zelig. Love Your Neighbor: Brooklyn, New York: Bnay Yakov Publications, 2004.

Schlegel, William. “The Land and the Bible: A Historical Geographical Companion to the Satellite Bible Atlas,” September 2013.

Walton, John H., Victor H. Matthews, and Mark W. Chavalas. The IVP Bible Background Commentary: Old Testament. (E-Sword). Downers Grove, Ill: IVP Academic, 2000.

  1. William Schlegel, “The Land and the Bible: A Historical Geographical Companion to the Satellite Bible Atlas,” September 2013, loc. Map 2-2.,↩︎

  2. John H. Walton, Victor H. Matthews, and Mark W. Chavalas, The IVP Bible Background Commentary: Old Testament, (E-Sword) (Downers Grove, Ill: IVP Academic, 2000), loc. Gen 20:1. ↩︎

  3. Pliskin, 84. ↩︎

  4. The line from the movie is, “Mr. Corleone is a man who insists on hearing bad news immediately.” ↩︎