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Genesis 21:1-34

I Said What I Said

This sermon from Genesis 21 explores God's unwavering faithfulness through Abraham's journey, highlighting how God always fulfills His promises in His perfect timing, despite human failings and long periods of waiting. It examines three aspects of this faithfulness: in the celebration of Isaac's birth, in providing for Hagar and Ishmael in the wilderness, and in establishing Abraham in a foreign land. The message emphasizes trusting God's Word completely, even when circumstances are challenging, and embracing the spiritual discernment necessary to align with God's covenant promises.

John Lee · February 1, 2026 · 47 min

If you have a Bible, you can go and grab it and turn it to the book of Genesis, chapter 21. If you don't have a Bible, you can use a pew Bible that's in front of you. If you don't own a Bible, we're very glad that you're here. Feel free to just keep that Bible; we would love for that to be our gift to you. We would love for you to be able to have a copy of God's Word that you can keep for yourself and read and see what the Lord has to say to you.

We'll be looking at the very first book of your Bible. So if you flip past the table of contents and go into Genesis, we'll be looking at chapter 21. The big number is the chapter number, and little numbers are the verse numbers. We'll be looking at the entire chapter, Genesis 21. I'll be reading from verse one.

The Lord came to Sarah as he had said, and the Lord did for Sarah what he had promised. Sarah became pregnant and bore a son to Abraham in his old age, at the appointed time God had told him. Abraham named his son who was born to him—the one Sarah bore to him—Isaac. When his son Isaac was eight days old, Abraham circumcised him, as God had commanded him. Abraham was a hundred years old when his son Isaac was born to him. Sarah said, “God has made me laugh, and everyone who hears will laugh with me.” She also said, “Who would have told Abraham that Sarah would nurse children? Yet I have borne a son for him in his old age.” The child grew and was weaned, and Abraham held a great feast on the day Isaac was weaned. But Sarah saw the son mocking—the one Hagar the Egyptian had borne to Abraham. So she said to Abraham, “Drive out this slave with her son, for the son of this slave will not be a coheir with my son Isaac!” This was very distressing to Abraham because of his son. But God said to Abraham, “Do not be distressed about the boy and about your slave. Whatever Sarah says to you, listen to her, because your offspring will be traced through Isaac, and I will also make a nation of the slave’s son because he is your offspring.” Early in the morning Abraham got up, took bread and a waterskin, put them on Hagar’s shoulders, and sent her and the boy away. She left and wandered in the Wilderness of Beer-sheba. When the water in the skin was gone, she left the boy under one of the bushes and went and sat at a distance, about a bowshot away, for she said, “I can’t bear to watch the boy die!” While she sat at a distance, she wept loudly. God heard the boy crying, and the angel of God called to Hagar from heaven and said to her, “What’s wrong, Hagar? Don’t be afraid, for God has heard the boy crying from the place where he is. Get up, help the boy up, and grasp his hand, for I will make him a great nation.” Then God opened her eyes, and she saw a well. So she went and filled the waterskin and gave the boy a drink. God was with the boy, and he grew; he settled in the wilderness and became an archer. He settled in the Wilderness of Paran, and his mother got a wife for him from the land of Egypt. At that time Abimelech, accompanied by Phicol the commander of his army, said to Abraham, “God is with you in everything you do. Swear to me by God here and now, that you will not break an agreement with me or with my children and descendants. As I have been loyal to you, so you will be loyal to me and to the country where you are a resident alien.” And Abraham said, “I swear it.” But Abraham complained to Abimelech because of the well that Abimelech’s servants had seized. Abimelech replied, “I don’t know who did this thing. You didn’t report anything to me, so I hadn’t heard about it until today.” Abraham took flocks and herds and gave them to Abimelech, and the two of them made a covenant. Abraham separated seven ewe lambs from the flock. And Abimelech said to Abraham, “Why have you separated these seven ewe lambs?” He replied, “You are to accept the seven ewe lambs from me so that this act will serve as my witness that I dug this well.” Therefore that place was called Beer-sheba because it was there that the two of them swore an oath. After they had made a covenant at Beer-sheba, Abimelech and Phicol, the commander of his army, left and returned to the land of the Philistines. Abraham planted a tamarisk tree in Beer-sheba, and there he called on the name of the Lord, the Everlasting God. And Abraham lived as an alien in the land of the Philistines for many days. — Genesis 21:1-34 (CSB)

Let's pray. Lord, we do call upon your name, on the name of the everlasting God. We know, Lord, that without your help, we will be found to be utterly faithless. Our ears would be closed to your Word. So we do ask, Lord, that you would come and speak to us this morning. Help us to understand and to treasure you. Pray this in Jesus' name. Amen.

We've been going through the book of Genesis for a long time. As we've been following the past nine chapters, following Abraham's life, we've seen example after example of God giving promises to Abraham about something that would happen in the future. In every single chapter, over the course of 25 years of Abraham's life, he's had to wait for God to come through on what he said that he would do. Now, in chapter 21, after nine chapters of waiting, after 25 years of waiting for God to come through, God finally does what he said that he would do. By seeing what God did and by seeing God doing what he said that he would do, we get to see, by extension, that God is always faithful to all of his promises. We actually see three examples of God's faithfulness here in this story.

First, we get to see God's faithfulness in feast as he fulfills his promises to Abraham—faithfulness in feast. Second, we see that God is faithful in famine, as he interacts with Hagar and Ishmael. And thirdly, we see that God is faithful in foreign lands, as Abraham still has to wait for God to fulfill the entirety of the promise that God had promised him.

God's Faithfulness in Feast: The Birth of Isaac

Let's start with point number one: faithful in feast. Read with me from verse one.

The Lord came to Sarah as he had said, and the Lord did for Sarah what he had promised. Sarah became pregnant and bore a son to Abraham in his old age, at the appointed time God had told him. Abraham named his son who was born to him—the one Sarah bore to him—Isaac. When his son Isaac was eight days old, Abraham circumcised him, as God had commanded him. Abraham was a hundred years old when his son Isaac was born to him. — Genesis 21:1-5 (CSB)

They had been listening to God's words for over 20 years. Abraham and Sarah followed in faith. They've failed in sin. They've seen partial fulfillments in blessing the nations. And they have been patiently waiting for God to fulfill what he said that he would do: provide a seed, a promised offspring to them. And now in chapter 21, that seed has finally come.

Suddenly, it reads like all of these covenant promises that God gives to Abraham in Genesis 17 suddenly dump like a bucket of cascading water onto Abraham and his wife, Sarah. God says in Genesis 17 that he will bless Sarah, and then God comes to Sarah in Genesis 21. God says that Sarah will bear Abraham a son in chapter 17, and Sarah bears Abraham a son in chapter 21. He tells Abraham to name him Isaac in chapter 17, and Abraham names him Isaac in chapter 21. God tells him to circumcise his son in chapter 17, and Abraham does it in chapter 21. God tells him it will happen in the next year when Abraham was 99 years old in chapter 17, and it says in chapter 21 that Abraham was 100 years old. If you're bad at math, that's one more than 99.

Every single setup in chapter 17 has a payoff, and it all happens in the beginning of this chapter in chapter 21. And the focus of what happens here is not on all that Abraham and Sarah did. You can imagine telling this story in a way that focuses on Abraham and Sarah's experience after decades of awaiting, the tears of joy after holding their son, Abraham's sigh of relief as his shoulders drop in the face of all that the Lord has done for them. But the story does not do that. That's not the focus in these first chapters.

In fact, look at verses 1 through 3 and how they describe this great fulfillment for Abraham and Sarah. There is a focus, and it's not on Abraham and Sarah at all. It says that the Lord came as he said, the Lord did what he promised, and that the son came at the appointed time that God had told him. In other words, the reason why these promises came to pass, the reason why Abraham and Sarah were able to receive this remarkable gift of a son, wasn't because of anything that *they* did. If anything, if you look at what they *did* do, most of their proactive action and decisions actively worked against God's promises, not for them.

Abraham gives up Sarah to a foreign king. Sarah tries to create a son through another woman, Hagar. All the times that Abraham and Sarah tried to

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