A great suspense has been building ever since the Lord announced to Abraham (originally Abram until Gen. 17) in Genesis 12 He would make of him a great nation. In Genesis 11:30 Moses had just emphasized the tragic fact about Abraham’s wife that “Sarai was barren; she had no child.” Yet after Abram arrived in Canaan at age 75, “Then the LORD appeared to Abram and said, “To your descendants I will give this land.”” (Gen. 12:7). Where would these descendants come from?
In Genesis 13 after Abraham had separated from his nephew Lot again the Lord promised, “for all the land which you see I give to you and your descendants forever. And I will make your descendants as the dust of the earth; so that if a man could number the dust of the earth, then your descendants also could be numbered.” (Gen. 13:15-16). In Genesis 15 the word of the Lord came to Abraham in a vision saying, “one who will come from your own body shall be your heir” (Gen. 15:4) and that his descendants would be as innumerable as the stars in the sky (Gen. 15:5). Abraham believed God’s word. But when would God fulfill this promise?
In Genesis 16 Abraham and Sarah tried to produce their promised child by means of the flesh when Sarah gave her maidservant Hagar to Abraham. She bore Abraham a son named Ishmael causing great strife in the family between Sarah and Hagar. In Genesis 17 the Lord again appears to Abraham when he was 99 years old and Sarah was 89 saying that He would bless Sarah and also give Abraham a son by her. This was so incredible that “Abraham fell on his face and laughed” (Gen. 17:17). He asked that Ishmael might be the one (Gen. 17:18), but God answered, “No, Sarah your wife shall bear you a son, and you shall call his name Isaac; I will establish My covenant with him for an everlasting covenant, and with his descendants after him.” (Gen. 17:19). Then God gave Abraham the schedule: “Sarah shall bear (this child) to you at this set time next year” (Gen. 17:21).
In Genesis 18 the Lord said the same thing again in the hearing of Sarah “I will certainly return to you according to the time of life, and behold, Sarah your wife shall have a son” (Gen. 18:10). Sarah also laughed. How could this be? The Lord censured her doubts asking “Is anything too hard for the Lord?” The answer of course is “No, nothing is too hard for the Lord.”
All these promises which God reiterated and clarified over the years were comforting, no doubt. But they also increased the anticipation. But Abraham and Sarah have been waiting for 25 years. Now finally, ten chapters after we began this journey with Abraham we see that promise fulfilled.
Genesis 21 divides easily into three parts. One, the story of the birth of Isaac in Genesis 21:1-7. There we see that God is faithful to fulfill His promise. Two, the story of the casting away of Ishmael found in Genesis 21:8-21. There we see the pain of separating from the world of the flesh. And three, in the story of the covenant transacted between Abraham and Abimelech in Genesis 21:22-34 we see God providing for and protecting Abraham.
1. The Birth of the Promised Son (Gen. 21:1-7)
In Genesis 21:1-2 we finally hear the news that we have been waiting for: “And the LORD visited Sarah as He had said, and the LORD did for Sarah as He had spoken. For Sarah conceived and bore Abraham a son in his old age, at the set time of which God had spoken to him.”
Notice the emphasis here on what the Lord has done: “And the LORD visited Sarah … and the LORD did for Sarah.” The birth of Isaac was an act of God. The Lord had miraculously enabled Sarah to conceive Abraham’s child. God did it. Maybe that is why the Lord took so long in fulfilling the promise: He ensured they would know that this child was from the Lord. It was impossible any other way.
The key here is the phrase, “as He had spoken.” Three times Moses emphasizes what the Lord had promised: “… as He had said … as He had spoken … of which God had spoken to him.” Do you see the certainty of God’s Word? It was God who promised the child; it was God who accomplished His word.
The Lord is faithful. He always keeps His promises. He cannot lie or change His mind. We might doubt His faithfulness with the passing of time, but the story of the long awaited birth of Isaac demonstrates that God will always keep His promises, even if it seems humanly impossible and even if the wait seems unreasonably long. God isn’t bound to our timetable, He works in His timing. With us, 25 years might seem like forever. With God, a thousand years is as a day (2 Pet. 3:8). Clearly, God is not a hurry! He is always on time. Sarah conceived and gave birth to Isaac “at the set time of which God had spoken to him.” God’s purposes are never delayed, they are done right on schedule.
Abraham’s response to God’s gift was faithful obedience:
3 And Abraham called the name of his son who was born to him–whom Sarah bore to him–Isaac. 4 Then Abraham circumcised his son Isaac when he was eight days old, as God had commanded him. 5 Now Abraham was one hundred years old when his son Isaac was born to him. (Gen. 21:3-5).
Isaac means laughter. His name reflects both their incredulous laughter when God told them Sarah would give birth at 90 and the subsequent laughter of joy when God did it. Circumcision was the sign of the covenant which the Lord had established with Abraham.
Sarah response showed her joy (Gen. 21:6-7) “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.”” When God does great things for you, you laugh with joy and others rejoice with you (Cole). I can imagine that for years many had laughed AT Abraham and Sarah because of their lack of children. Now that laughter of derision is turned to laughter of God’s provision.
The point is that God fulfills His promises. He is faithful. It is impossible that He will not keep His word. Rejoice! God fulfills His promises.
In the next part of the chapter we see …
2. Ishmael Sent Away (Gen. 21:8-21)
From the joy of Genesis 21:6-7 we transition rather abruptly to the pain and sadness of Genesis 21:8-21. Perhaps as many as three years have passed since Sarah gave birth to Isaac. Genesis 21:8 says, “So the child grew and was weaned. And Abraham made a great feast on the same day that Isaac was weaned.”
But an old conflict would put a damper on this celebration: “And Sarah saw the son of Hagar the Egyptian, whom she had borne to Abraham, scoffing.” (Gen. 21:9). If Isaac was about three years old then that makes Ishmael about sixteen. Ishmael is called a “boy” and a “lad” in these passage, but the Hebrew word can also be translated as “young man” (cf. Gen. 4:23). Picture him as a teenager. The word “scoffing” is a play on the name Isaac. Ishmael was laughing, making fun of Isaac—not in a nice way. Paul writes about this in Galatians 4:29 saying, “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.” Ismael was mocking the boy and was persecuting him. This caused the mama bear in Sarah to come to his defense: “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.””
This grieved Abraham to core. In Genesis 21:11 we read, “And the matter was very displeasing in Abraham’s sight because of his son.” It’s clear that Abraham loved Ishmael very much. The thought of sending him away with Hagar after 16 years pierced his heart. But he had to because God confirmed it (Genesis 21:12): “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.”” Steven Cole writes,
“This was the most difficult thing God had told Abraham to do in his 100 years. Although the text doesn’t say, I don’t think I’m off base when I picture Abraham with tears streaking down his weathered cheeks as he sends Hagar and Ishmael into the desert. As far as we know, this was the last time Abraham saw his son whom he had loved for 16 years. I don’t care how much you trust God, something like this hurts deeply. And you don’t get over it in a few days or even in a few years. Even though there was great joy over the birth of Isaac, Abraham suffered ongoing pain over the loss of Ishmael.”
Sixteen years earlier Abraham and Sarah had decided that God needed their help. Rather than trusting God to provide the promised son in His way and His timing, they sinfully ran ahead of God. Sin has its consequences. It brings conflict. It divides. It ultimately brings pain and grief. It especially hurts when God wants to remove from us our cherished deeds of the flesh.
God said Ishmael must go. But He also promised to bless Ishmael for Abraham’s sake: “Yet I will also make a nation of the son of the bondwoman, because he is your seed.” (Gen. 21:13).
Abraham had a habit of immediate obedience when God spoke to him. Genesis 21:14 says, “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.” I’m sure Abraham didn’t fully understand God’s reason for sending Ishmael away, just as later he didn’t understand God’s reason for asking him to sacrifice Isaac. But he obeyed without questioning God. There will always be conflict between my flesh (what I can do in my power) and the Spirit (what only God can do). The only way to resolve the conflict is obediently to put off the deeds of the flesh. (Cole).
Genesis 21:16b-21 tells the rest of the story of Ishmael:
Then she departed and wandered in the Wilderness of Beersheba. 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.” 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. 21 He dwelt in the Wilderness of Paran; and his mother took a wife for him from the land of Egypt.
Just as God had spoken to Hagar in Genesis 16 when she fled from Sarah, He graciously speaks again to her in her distress. Despite what God knew about the history of Ishmael’s offspring, He protected the boy because of His promise to Abraham. Again we see that God fulfills His promises not because of who we are, but because of who He is. It’s His grace.
What do we learn from this passage? God has separated Abraham and Ishmael that his heart would be wholly committed to the covenant being fulfilled in the son of promise, Isaac. You see, the loss of Ishmael forces Abraham to stop hedging his bets with regard to the promises of God, and sets us up for the drama of Genesis 22. There the Lord will ask Abraham to sacrifice Isaac, his only begotten son, as a burnt offering. When Abraham is climbing Mount Moriah with Isaac there is no other son to fall back on. Ishmael is gone. God breaks Abraham’s heart in order to build his faith. (Duncan).
Finally we see in Genesis 21 …
3. Abraham’s Treaty with Abimelech (Gen. 21:22-34)
Let me read these verses and just make a few brief comments:
22 Now it came about at that time that Abimelech and Phicol, the commander of his army, spoke to Abraham, saying, “God is with you in all that you do; 23 now therefore, swear to me here by God that you will not deal falsely with me or with my offspring or with my posterity, but according to the kindness that I have shown to you, you shall show to me and to the land in which you have sojourned.” 24 Abraham said, “I swear it.” 25 But Abraham complained to Abimelech because of the well of water which the servants of Abimelech had seized. 26 And Abimelech said, “I do not know who has done this thing; you did not tell me, nor did I hear of it until today.”
27 Abraham took sheep and oxen and gave them to Abimelech, and the two of them made a covenant. 28 Then Abraham set seven ewe lambs of the flock by themselves. 29 Abimelech said to Abraham, “What do these seven ewe lambs mean, which you have set by themselves?” 30 He said, “You shall take these seven ewe lambs from my hand so that it may be a witness to me, that I dug this well.” 31 Therefore he called that place Beersheba, because there the two of them took an oath. 32 So they made a covenant at Beersheba; and Abimelech and Phicol, the commander of his army, arose and returned to the land of the Philistines. 33 Abraham planted a tamarisk tree at Beersheba, and there he called on the name of the Lord, the Everlasting God. 34 And Abraham sojourned in the land of the Philistines for many days.
Notice first of all that Abimelech and his commander approach Abraham saying, “God is with you in all that you do.” (Gen. 21:22). Abimelech had taken note of how God cared for Abraham. This serves as a contrast to what Ishmael had done. Ishmael, the son of the flesh, mocked the son of promise. He thought little of the blessing of the LORD upon the house of Abraham. But Abimelech the foreign king saw it. He saw that Abraham was blessed of God. (Joe Anady).
Abimelech sought a treaty with Abraham because he did not ever wish to go to battle against him. To fight Abraham was to attack Abraham’s God and to have to contend with Him. On the other hand, to have an alliance with Abraham was to have God on his side.
But do you see the lesson this should have taught Abraham? Abraham had lied to Abimelech about Sarah because he thought that there would be no fear of God, and thus no protection of himself, in a land of pagans (cf. 20:11). God rebuked the unbelief of Abraham by this testimony from the lips of Abimelech. (Deffinbaugh). Abraham had feared for his life and for his wife among these “pagans” (Gen. 20:11). But God showed him that Abimelech recognized his favored status with his God and that Abimelech would not have done him harm on account of this. Not only would Abimelech not take another man’s wife, he would not even take a well that did not belong to him.
The world is watching the lives of believers. They watch our attitudes, our words, and our actions. How is your witness to them? Don’t despair! Although we care called to be holy, sinlessness was never a prerequisite for being a witness. Just because you’ve blown it with someone in the past doesn’t mean that you can’t be used later to influence that person toward God. In spite of Abraham’s past deception, Abimelech recognized God in his life.
In Genesis 21:33, Abraham planted a tree and “called on the name of the Lord, the Everlasting God.” Planting the tree was an act to remind Abraham of God’s faithfulness, especially in the everyday matter of providing the well which supplied the water for this tree to grow. A tree will usually be there for a long time, for generations to come. So Abraham calls the Lord, “the Everlasting God.” The new name of God bore witness to God’s unchanging faithfulness and to the fact that Abraham’s faith was not in Abimelech nor in the treaty between them, but in the eternal God.
Where are you placing your hope? In whom are you trusting? Trust in Jesus. Listen, all of us, like Abraham are sinners in need of a Savior. God didn’t wait until you were perfect to forgive you and accept you. No, while we were still sinners God sent His only begotten Son into this world to die for sinners. Jesus Christ took all our sin upon Himself on the cross. He did what you could never do for yourself. And now, alive from the dead, Jesus is the everlasting God who gives eternal life to all who believe in Him. God promised it and He fulfilled it. Won’t you trust in Him today?