The Birth Of Isaac

INTRO

In Genesis 1—19, we have discussed how the Seed, Christ, is carried as a theme throughout the book of Genesis. The Seed came through Abraham. Genesis 20 and 21 continues the theme of how God spared Abraham because he carried the Seed.

In Genesis 20, Abraham travelled to the Negev and told a half-lie to Abimelech—that Sarah was his sister. So Abimelech took her as a wife, and then Abimelech was about to die. But God came to Abimelech, and so he returned Sarah with loads of blessings and silver. And then because he made everything right, God healed Abimelech’s wife, and she was able to bear children. All this happened because of God’s hand of protection on Abraham because of the blessing that would come from him. Genesis 21 is the repeat of how God blessed Abraham, and we are a product of this blessing.

TEACHING

Genesis 21:1–5: Verse 1 records: “The Lord . . . did for Sarah what He had promised.” Remember when God showed up the last time? In Genesis 17:15–16, He promised that Sarah would produce nations and kings of peoples. In Genesis 18:14, God promised that in a year, she would have a son. Which brings us to Genesis 21:1—the year God promised. God had done what He said He would do. We can trust that God is constantly faithful to what He says. In verse 2, Sarah’s role now increased. Have you ever had a prophetic word spoken over your life, and then after some time, you saw it come to fulfillment? This is what happened with Sarah. “Sarah became pregnant and bore a son to Abraham in his old age, at the appointed time God had told him” (v. 2). It’s like when Jesus stood up in Nazareth and read the scroll of Isaiah and said now it is fulfilled. “At the appointed time”—it’s all in God’s timing. Remember what happened with Hagar and Ishmael? But now was the time.

Let’s review Genesis 12:1–3. What happened in Genesis 21 was because of Genesis 12. This was the fulfillment of a portion of Genesis 12. Follow God’s promises given in Genesis 17:7; Genesis 13:15–16; Genesis 15:4; and Genesis 17:19. Over and over and over, God kept His promise! What happened in Genesis 21:2? The everlasting covenant took off! Hebrews 11:8–9 confirmed that Isaac was a coheir to the promise that was given in Genesis 12. And that’s what we’re going to see unfold today.

In verse 3, Abraham named his son Isaac. Why? Because God told Abraham to name him Isaac (Genesis 17:19). Isn’t it cool when God speaks to us, and then we get to respond and do what He says? The question is, are we listening to Him? But as we’ve seen, Abraham wasn’t perfect. If God could use Abraham, He can use us too. We just have to be willing. In verse 4, when Isaac was eight days old, Abraham circumcised him in obedience to God’s command (Genesis 17:9–12). Abraham was obedient.

“Abraham was 100 years old when his son Isaac was born to him” (v. 5). God rewards patience. Even though Abraham went wrong with Hagar, God was still faithful. Abraham and Sarah waited 25 years to see the fulfillment of God’s promise. Hebrews 6:12 says to “be imitators of those who inherit the promises through faith and perseverance.” We want the blessings, but we’re not willing to persevere in the faith. James 1:3 promises that “the testing of your faith produces endurance.” We want to believe, but will we endure?

Warren Wiersbe said, “Trusting God’s promises not only gives you a blessing at the end, but it also gives you a blessing while you’re waiting.”¹Romans 4:17 revealed this was such a radical fulfillment of God’s promise! Abraham even considered himself as good as dead!

Genesis 21:6–7: “Isaac” means laughter. Constable said Isaac was a source of joy to his parents as fulfillment of the promised seed.²God is a God of miracles. Through these events, we can see a living link from Adam and Eve to Noah to Abraham and Sarah to Isaac (v. 7).

Genesis 21:8–10: Three years old was the typical age for weaning. When Isaac turned three, Abraham threw a great feast (v. 8). Sarah saw Ishmael mocking Isaac. To mock means to ridicule. Sarah saw Ishmael as a threat to Isaac. Back in Genesis 19:14, when the sons-in-law didn’t believe Lot, this was the same image. Later, in Judges 16:25, when the Philistines wanted Samson to entertain them, they wanted to make a mockery of him. Ishmael carried the seed of the serpent. The Muslims are descendants of Ishmael. But the Seed of the woman went to Isaac. Isaac carried the Seed, Christ. Ishmael would not be a coheir with Isaac (v. 10). According to the “laws of Lipit-Ishtar,” if a slave bears children, and the father then grants freedom to her and her children, the children of the slave shall not divide the estate with children of their former master.³

Genesis 21:11–13: “Now this was a very difficult thing for Abraham because of his son” (v. 11). Difficult means distressed, grievous, shaking. Abraham knew Ishmael was born of the flesh, whereas Isaac was born of the Spirit. This truth became more and more prominent as the seed unfolded. Notice this weird pattern that the firstborn was rejected in favor of the second born: Cain and Abel, Ishmael and Isaac, Esau and Jacob, Manasseh and Ephraim.

Verse 12 explains that it came down to divine choice. God chose Abraham and then Isaac. Hagar was the mother of Ishmael. Sarah was the mother of Isaac.The child with Hagar resulted from Abraham and Sarah’s coercion to force the fulfillment of the promises on their own. With Sarah and Abraham, there was freedom and there was waiting.

In verse 13, God said He would still bless Ishmael, even though Ishmael was not part of His plan. The problem comes when we aren’t patient and do it our own way instead of God’s. Because Hagar and Abraham did not wait, we have Islam today. Really because Sarah said, “I can’t wait.” So now we have this tension. We have tension because of someone else’s sin. Please don’t forget that your sin will always impact someone else.

Genesis 21:14–16: Before sending Hagar and Ishmael away, Abraham provided them with bread and waterskins for the journey. The skins would have contained about three gallons or 24 pounds of water. Once it was gone, Hagar left Ishmael under a bush. Bruce Waltke said Hagar basically abandoned her child.⁴

Genesis 21:17–21: God heard their cries (v. 17). God still wants to redeem everyone. God promised to make Ishmael a great nation. God took care of this people group (v. 18). He provided sustenance. God opened the eyes of Hagar and provided a well. Even though they were rejected, He saw them and cared for them. This sounds to me like the woman at the well. In John 4, Jesus met the Samaritan woman at the well. Though others did not value her, Jesus knew this person still mattered. He promised her living water. Even if you’re functioning in the seed of the serpent, Jesus still offers the water of life. John 7:37–39, Jesus said: “If anyone is thirsty, he should come to Me and drink! The one who believes in Me, as the Scripture has said, will have streams of living water flow from deep within him.”

CLOSING

Those who believe in the Seed, Christ, will receive the Spirit. This Seed, that came through Abraham is available to everyone. Wiersbe said, “Hagar is certainly a picture of the needy multitudes in the world today: wandering, weary, thirsty, blind, and giving up in despair.”⁵God cares for everybody. He cares for the Hagars and the Sarahs. What Jesus promised through the pre-incarnate Christ . . . He did. Sarah became a mom, and Isaac was the chosen one. My prayer is that you see God’s hand was obviously on Isaac, but the message of hope is available for all.