A Son Through Sarah

Are we okay with God being as big as He wants to be?

Chris Hutchison on March 12, 2023
A Son Through Sarah
March 12, 2023

A Son Through Sarah

Passage: Genesis 17:15-18:15
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Two weeks ago, in Genesis 16, we looked at Ishmael and how Hagar was given his name before he was born. And I mentioned how this put Ishmael in a very small group in Scripture which included several others. And when I counted and listed them, I didn’t include John the Baptist, whose name had been given to his father Zechariah before he was born.

And more than one of you reminded me afterwards that I missed that. And that made me really happy that you caught my mistake. It shows that you’re listening. It shows that you know what’s in the Bible. And it shows that you want to make sure that what’s being said from the pulpit is true and lines up with what’s in the Bible.

This was a minor mistake, but I was so pleased that you caught it that I think I’ll make mistakes more regularly just to keep you sharp. You know I’m kidding. But I was happy about that and I hope you never stop expecting whoever steps into this pulpit to bring you word of God and nothing less.

And that’s what we want to do this morning as we go back to Genesis 17. Today’s message is built around two encounters that Abraham had with God, with an interlude in between. This first encounter is just a continuation of where Josh left us last week. Last week we heard how God changed Abraham’s name and reaffirmed His covenant with Him and gave him the covenant sign of circumcision, and today that revelation from God continues as God makes his most specific promises yet to Abraham about his promised son.

A. First Encounter (17:15-21)

And that encounter continues in verse 15 as the Lord keeps speaking to a speechless Abraham. And what he says here is probably the most surprising statement yet as He gives Abraham an promise for Sarah.

1. A Promise for Sarah (vv. 15-16)

Who’s Sarah you ask? I thought Abraham’s wife was named Sarai? Well, look at verse 15. “And God said to Abraham, ‘As for Sarai your wife, you shall not call her name Sarai, but Sarah shall be her name” (Genesis 17:15). “Sarai” and “Sarah” both have the same meaning, which is “princess.” So the meaning of her name doesn’t change, but the fact that it does change is a marker that something really big is changing in her life. Which is, in verse 16, that God is going to bless her and give Abraham a son by her.

And not just a single son, but “she shall become nations; kings of peoples shall come from her.” Those were the promises given to Abraham in verse 6, and here, for the first time, God makes very clear that these international promises will come through the child that Abraham will bear with his wife Sarah. Look at how that’s emphasized in verse 16, with “her,” “she,” “her” repeated in rapid-fire.

The promises to Abraham will not come through Hagar but through the miraculous child of Sarah.

And this child will be miraculous. Sarah is around 90 right now, as we find in verse 17. 90-year-old women don’t get pregnant. Even if we consider that Sarah lived for 127 years and guess that she aged more slowly, she still could be the equivalent of around 60 years old right now. She’s well past menopause, as she acknowledges plainly in the next chapter.

Make no mistake: what God is promising here is a miracle, full stop.

2. A Question from Abraham (vv. 17-18)

And how does Abraham respond? Verse 17-he falls on his face again. Evidently he’s gotten up since verse 3 when he fell on his face again.

It’s tough to know right now whether Abraham is falling facedown because he’s amazed or shocked or in awe or just completely bewildered. Similarly, it’s tough to know exactly what’s behind his laugh in verse 17, where he laughs and says to himself, “Shall a child be born to a man who is a hundred years old?”

Is this a laugh and a question of unbelief, as if he’s laughing at how ridiculous this suggestion is and saying, “Ya, right”? Or is this a laugh and question of shock and amazement? I’ve seen people do that many times—when they get told some really amazing news, and their eyes get big and they cover their month and they start to laugh because it seems to good to be true.

What is clear is that Genesis is showing us Abraham struggling take this in in a very human way. The significance of this miracle is landing on him and he’s processing it the way a normal person would.

It’s very interesting to see what he says next in verse 18—“And Abraham said to God, ‘Oh that Ishmael might live before you!’” This is Abraham’s question or request for God, and this leads me to believe that Abraham is not disbelieving what he’s being told. He’s processing it. And he’s realizing that if his son through Sarah is going to be the heir of the promises, then what about Ishmael?

Ishmael is about thirteen years old by now. Abraham has gotten used to the idea that this is his son. This is his heir. It was all about Ishmael.

And the weight of his bad decisions is slamming into him. He didn’t wait for God. He went ahead and had a son through Hagar. God is delivering on His promise anyways. And that’s going to create tension.

So—couldn’t God be content with Ishmael? Couldn’t he just be the heir? Couldn’t he just live on before the Lord without complicating things further?

So again, with this request in verse 18, I don’t think Abraham is disbelieving that God can give him a son through Sarah. I think Abraham is wrestling with what that means.

3. A Covenant with Isaac (v. 19)

And what does God say to him in verse 19? “God said, ‘No, but Sarah your wife shall bear you a son, and you shall call his name Isaac.”

There it is. One more key place in the Scriptures where a child’s name is revealed before his birth. Isaac (יִצְחָק) means “he laughs,” which at this point is a reference to Abraham’s reaction when he heard he would have a son. We’ll see how the theme of laughing comes up more than once as this story develops.

And what God goes on to confirm is that it is through Isaac, not Ishmael, that His covenant will be established. Verse 19, half-way through: “I will establish my covenant with him as an everlasting covenant for his offspring after him.”

Do you get the significance of this? Up in verse 7 God told Abraham he’d establish his covenant with him and his offspring after him for an everlasting covenant.

And what God is saying here is that this covenant with Abraham’s offspring will not include all of his offspring. The covenant will be established with Isaac and his offspring. And we know that the covenant didn’t include all of Isaac’s offspring either. Esau was not a part of the covenant. God did not establish his covenant with him, but with Jacob.

4. A Future for Ishmael (vv. 20-21)

Now this doesn’t mean Ishmael gets nothing at all. There is a future for Ishmael. There are some benefits that come from being Abraham’s son, even if God chooses not to establish a covenant with him. We see this in verse 20 when the Lord says, “As for Ishmael, I have heard you.” We should stop there and enjoy the wordplay. “Ishmael” means “God hears,” and here God is demonstrating that by listening to Abraham. And what does He say? “Behold, I have blessed him and will make him fruitful and multiply him greatly. He shall father twelve princes, and I will make him into a great nation.”

This is further unpacking the promises God made to Hagar about her son. Ishmael has already be blessed and will be multiplied and be the father of royalty.

“But,” verse 21, “But I will establish my covenant with Isaac, whom Sarah shall bear to you at this time next year.”

Notice in this final statement that God’s promises to Abraham about his son have gotten the most specific they’ve ever gotten? Back in chapter 12 they were wide open: “I will make if you a great nation” (Genesis 12:2). And slowly, as Abraham and Sarah have gotten older and older, the promises from God have gotten more and more specific until this verse, where Abraham is told in no uncertain terms that Isaac, not Ishmael, will be the son of promise, that he will be born through Sarah, and that he will be born in a years time.

B. Interlude: An Act of Obedience (vv. 22-27)

And at this point God has concluded this encounter with Abraham, and he “went up from” him as verse 22 says. And so we move into the second major part of our passage this morning, an interlude where we see Abraham obeying. Verses 23-27 tell in detail how Abraham—at ninety-nine years of age—and Ishmael—at thirteen years of age—and all the men in Abraham’s household were circumcised.

We don’t need to elaborate on why this would have been uncomfortable. Some of Abraham’s men might have complained. But Abraham obeyed God. He obeyed right away: verse 26 says this happened “that very day.” And he obeyed all the way. Verse 27: “And all the men of his house… were circumcised with him.”

We should want to cheer at this moment. Genesis hasn’t hidden from us the stumblings of Abraham. But it also takes the time to draw attention to his obedience. And we should see that the overall overall direction of Abraham’s life was marked by faith-filled obedience. When he stumbled, he got up and continued to trust and obey.

We could pause here for a while on how this should be encouraging to us. No matter how far you’ve stumbled, you’re only one step of faith-filled obedience away from being back on the path, following the Lord. Don’t let Satan make you think that you’ve wasted too many chances, and so you might as well just stay down. Choose to say yes to God today, with just one step of faith-filled obedience. It’s never too late for that.

C. Second Encounter (18:1-15)

And with that, we move into the second encounter with God Abraham has in this passage. This encounter is very unique in that it’s not a vision. It’s not “the word of the Lord coming to Abraham.” No, this time the Lord actually appears to Abraham in bodily form. It’s unclear whether Abraham even knows who it is when He shows up. But as time goes on Abraham becomes aware that this guest of his is no mere mortal.

1. A Visit from Strangers (vv. 1-8)

But let’s see where it begins in the beginning of chapter 18. “And the Lord appeared to him by the oaks of Mamre, as he sat at the door of his tent in the heat of the day. He lifted up his eyes and looked, and behold, three men were standing in front of him” (Genesis 18:1-2). These men are standing in front of his tent, which is the equivalent of knocking on his door. They are seeking hospitality.

And in the Middle East, up to the present day hospitality is a really big deal. Especially when a stranger seeks hospitality from you, you don’t see it as an interruption or inconvenience. You see it as a privilege to make yourself their servant and to do whatever you can to care for them.

And so halfway through verse 2 we see Abraham put this into practice as he springs into action. “When he saw them, he ran from the tent door to meet them and bowed himself to the earth and said, ‘O Lord, if I have found favor in your sight, do not pass by your servant. Let a little water be brought, and wash your feet, and rest yourselves under the tree, while I bring a morsel of bread, that you may refresh yourselves, and after that you may pass on—since you have come to your servant.’ So they said, ‘Do as you have said’” (Genesis 18:2–5).

So at this point it’s unclear whether Abraham is just being a good host and humbling himself like he would with anybody. It’s also possible he’s begun to discern that these strangers are very special people, because what he does next is do quite a bit more than bring a little water and a morsel of bread. Instead, he prepares a whole feast for them.

“And Abraham went quickly into the tent to Sarah and said, ‘Quick! Three seahs of fine flour! Knead it, and make cakes.’ And Abraham ran to the herd and took a calf, tender and good, and gave it to a young man, who prepared it quickly. Then he took curds and milk and the calf that he had prepared, and set it before them. And he stood by them under the tree while they ate” (Genesis 18:6–8).

In my notes this week, I wrote “lol” above the word “quick.” To us, “quick” means ordering a pizza. Or maybe sticking leftovers in the microwave. But here, a “quick” mean involves kneading cakes, by hand, out of about 22 litres of flour, butchering a calf, cooking up the meat, and serving that with cheese and milk.

If you’ve eaten mediterranean food, your taste buds are tingling right now. This would have been so good. And Abram, acting like a servant, stands by while these strangers eat.

This is such a great display, like we’ve seen, of middle-eastern hospitality. Another element that could be happening here is that God is literally eating a covenant meal in Abraham’s presence. In the ancient world, meals were often eaten after a covenant was made. And after God confirms His covenant with Abraham in Genesis 17, it’s quite possible to see this as a celebratory covenant meal that further seals this relationship between God and Abraham.

2. Another Promise for Sarah (vv. 9-11)

Now look at what comes next, in verse 9: “They said to him, ‘Where is Sarah your wife?” And he said, ‘She is in the tent.’ The Lord said, ‘I will surely return to you about this time next year, and Sarah your wife shall have a son’” (Genesis 18:9–10).

Notice how these guests already know who Abraham’s wife is and what her name is? And all doubt about who these visitors are vanishes when in verse 10 “The Lord said, ‘I will surely return to you about this time next year, and Sarah your wife shall have a son’” (Genesis 18:10).

There is is. Another promise for Sarah. Basically the same promise Abraham heard from the Lord before, but now it’s being delivered in person, and not just to Abraham but to Sarah as well.

3. A Question from Sarah (v. 12)

“And Sarah was listening at the tent door behind him” says the rest of Genesis 18:10. This might be the first Sarah is hearing of this. And how does she respond?

Before we see her response, the text makes sure to remind us of just how old Sarah was. Verse 11: “Now Abraham and Sarah were old, advanced in years. The way of women had ceased to be with Sarah.” Sarah is way past the age where she can bear a child. And “So,” verse 12, Sarah laughed to herself” (Genesis 18:12). Sarah responds much like Abraham when she considers the idea of her, at her age, and Abraham, and his age, conceiving a child together. She laughs. Once again, that’s important because of Isaac’s name, which means “He laughs.” Like his dad, Isaac’s mom laughs when she first hears about his birth.

And like Abraham, Sarah asks herself a question when she hears this news. The rest of verse 12 describes Sarah asking, “After I am worn out, and my lord is old, shall I have pleasure?” (Genesis 18:12b).

This sounds similar to Abraham’s question back in 17:17. But it’s far more certain here, from what comes next, that Sarah’s question from from a place of unbelief. It’s more like, “Seriously? How could that ever happen?” This sounds like one big joke to Sarah.

4. A Response from the Lord (vv. 13-15)

But God hears and knows. And in verse 13 “The Lord said to Abraham, ‘Why did Sarah laugh and say, “Shall I indeed bear a child, now that I am old?” Is anything too hard for the Lord? At the appointed time I will return to you, about this time next year, and Sarah shall have a son’” (Genesis 18:13–14).

There’s a few things we want to notice here in the Lord’s response. First, the Lord heard her. She can’t hide anything from Him. Second, the Lord responds to Abraham about her questioning. That suggests that Abraham, as Sarah’s husband, had some responsibility for her unbelief.

Next, notice how God asks two questions before He makes a statement. First question—“Why did she laugh?” In other words, she had no good reason to laugh. Second question—“Is anything too hard for the Lord?” What’s the answer to that question? A clear no. Nothing is too hard for Him. So if He wants a couple of senior citizens to have a baby, that’s going to happen.

And that is what’s going to happen, per God’s final statement, where He simply repeats what He said before. He is going to return, and Sarah is going to have a son. End of story.

This encounter ends with Sarah trying to deny it, but God won’t let her. His final words from verse 15 ring in the air—“No, but you did laugh”—which leave us hanging until “He laughs” is born in chapter 21.

And so I hope we can see just how important today’s passage is for the story of Abraham and Sarah. It moves their story along in really important ways. Despite their stumbles with Hagar, God’s plan to give the two of them a son moves ahead, and nothing—not even their old bodies, well past the age of bearing children—are able to stop him.

D. Isaac, Not Ishmael: The Enduring Truth of God’s Choice

But this all does introduce a big question, doesn’t it. God’s decision to give them Issac and continue the covenant through him means that Ishmael does not get to be the son of promise. He does not get to be a part of the covenant.

Remember in verse 16, when God told Abraham that the covenant promises would flow through a son of Sarah, and when Abraham asked that Ishmael might live before God as the son of promise, God literally said “no”? Even though Ishmael was Abraham’s first born son, and even though he would receive some blessing, he would not be a part of this covenant. Instead, that covenant would be established with Isaac and not Ishmael, something God repeats again in verse 21.

In other words, back in chapter 17:7, when God had told Abraham, “I will establish my covenant between me and you and your offspring after you throughout their generations for an everlasting covenant, to be God to you and to your offspring after you,” he did not mean that each and every one of Abraham’s physical offspring would be a part of this covenant. God would choose some but not all of Abraham’s offspring to be included in the covenant. Isaac, not Ishmael. Later on Jacob, not Esau.

The Apostle Paul picks up on this part of Genesis in Romans 9 to help explain a really difficult issue in his day. 2,000 years later, the Messiah Jesus had finally arrived. He had died and risen again and fulfilled the Scriptures that had been pointing to Him all along. And… most of the Jewish people of the day didn’t believe Him. The leaders in Israel killed him. And Paul had the Jewish leaders in town after in try to do the same with him when he preached Christ to them.

And in Romans 9, he’s really wrestling with this. He says in Romans 9:2 that he has “great sorrow and unceasing anguish in” his heart because of “my brothers, my kinsmen according to the flesh” (v. 3). After all, he says in verse 4, “They are Israelites,” and they have received so many blessings from their physical lineage.

So why are so many of them refusing to find salvation in their messiah? Listen to how Paul explain this in verse 6: “…For not all who are descended from Israel belong to Israel, and not all are children of Abraham because they are his offspring, but ‘Through Isaac shall your offspring be named.’ This means that it is not the children of the flesh who are the children of God, but the children of the promise are counted as offspring. For this is what the promise said: ‘About this time next year I will return, and Sarah shall have a son’” (Romans 9:6-9).

So you see what Paul is doing here? He’s quoting form Genesis, including the very passage we studied today, to make a point: not all of Abraham’s physical offspring are children of God. In Paul’s day, and in Abraham’s day, it’s the children of the promise are counted as offspring, not just the children of the flesh.

Now maybe you could say that Issac was chosen over Ishmael because Ishmael came from another woman, from Hagar. But Paul dispels that idea in verse 10 when he talks about what happened to Isaac’s children themselves: “And not only so, but also when Rebekah had conceived children by one man, our forefather Isaac, though they were not yet born and had done nothing either good or bad—in order that God’s purpose of election might continue, not because of works but because of him who calls— she was told, ‘The older will serve the younger.’ As it is written, ‘Jacob I loved, but Esau I hated’” (Romans 9:6–13).

Jacob and Esau both came from Isaac and Rebekah. And yet before they had done anything good or bad, God chose one and not the other. Why? It wasn’t because of their works. It was because of him who calls. It came down to God’s choice.

And that gets even clearer in verse 15-18: “For he says to Moses, ‘I will have mercy on whom I have mercy, and I will have compassion on whom I have compassion.’ So then it depends not on human will or exertion, but on God, who has mercy. For the Scripture says to Pharaoh, ‘For this very purpose I have raised you up, that I might show my power in you, and that my name might be proclaimed in all the earth.’ So then he has mercy on whomever he wills, and he hardens whomever he wills.”

Now I’ll admit, that is a tough pill for us to swallow. We’re so used to choosing our own leaders and charting our own destiny. For some Christians whose whole understanding of the Christian life comes down to our choices. And so the idea that everything actually comes down to God’s choice can be really unsettling.

It was unsetting to people back in Paul’s day, too. Verse 19: “You will say to me then, ‘Why does he still find fault? For who can resist his will?’”

That’s a great question. And how does it get answered? Verse 20: “But who are you, O man, to answer back to God? Will what is molded say to its molder, ‘Why have you made me like this?” Has the potter no right over the clay, to make out of the same lump one vessel for honorable use and another for dishonorable use? What if God, desiring to show his wrath and to make known his power, has endured with much patience vessels of wrath prepared for destruction, in order to make known the riches of his glory for vessels of mercy, which he has prepared beforehand for glory—” (Romans 9:19–23).

God is the potter. We are the clay. God has the right to make what he wants out of the clay. And if God wants to make vessels of wrath, prepared for destruction, so that He can show His great grace to the vessels of mercy which He’s formed and prepared for glory, He can do that.

Now some people still get really chewed up at this point, because Romans 9 has been talking about little babies and you can get carried away with this idea that the world is full of these basically good people trying to get into heaven, and God turns a bunch of people away just because He can. That’s where we need to go back to Romans 1 and 2 and 3 and remember that the world is actually full of bad people who are trying to get away from God as fast as they can, and in His mercy He chooses some and saves them.

And He doesn’t save us against our wills. He saves our wills themselves. He brings us from death to life and shines the light of the gospel into our hearts so that we see and believe and make the meaningful choice to follow Him. But we only do that because He first chose us out of His good and sovereign will.

I know this can be hard to believe. Some of you this morning might really struggle with this. So I just want to ask you a question. If this is what the Bible taught, beyond a shadow of a doubt, would you believe it? In other words, are you okay with God being as big and powerful and sovereign as He wants to be?

And if your answer is yes, then I encourage you to keep wrestling with this, keep reading what God has said about this, keep praying for understanding on this. But if you’re at least willing for God to be as big as He wants to be, you’re in a safe place as you figure out what that actually looks like in His word.

But on the other hand, if you’re not in that spot, if instead you’re heart would say “I don’t care what the Bible says, I’m in charge of my life and no God is going to make choices for me,” I would caution you that that’s a dangerous spot to be in, for obvious reasons. We want to make sure that we don’t try to tell God the way it’s going to be. We don’t think that we can decide the way things are. When the Bible confronts some deeply-held assumptions in our hearts, we need to be at least open to the possibility of having God change our minds.

Now, here’s why this is important. It’s not just important for understanding what happened with Isaac and Ishmael, or even the Jewish people alive in Paul’s day. It’s important to give us confidence as we take our part in the mission of God today.

Paul believed that God was sovereign over who got saved and who didn’t get saved. And that gave Him confidence to go out into the whole world and preach the gospel in some really dangerous places. Because if God had chosen people from every tribe and nation and people and language, then nothing could stop them from coming to believe.

I know that so often we shrink back from sharing gate gospel with people because we’re afraid. And this truth is a major antidote to that fear. We can share the gospel widely and boldly, knowing that those whom God has chosen must and will believe.

And by the way, this morning, if you don’t know Christ, you don’t have to sit around to figure out if you’ve been chosen or not. You just need to believe the good news and come to Jesus to be saved. And when you do that, that’s when you realize you were chosen.

Now finally, this truth is so important for our own hearts. If we know Christ, and we’re walking with Him, it’s not because we were smart enough to figure some things out that the rest of the world is too dumb to see. No, it’s because we were dead and God made us alive, and He gets all the glory for our salvation. When we get to heaven, we’ll be praising Him and Him alone.

And that’s where we’re going in our final song this morning. Not proud smugness that we’ve got it all figured out, but humble worship that God would save us.

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