In Galatians 4, Paul uses Isaac and Ishmael as an allegory: Isaac represents the promise and grace, Ishmael represents the flesh and law, and the bondwoman and her son must be cast out.
Les Feldick teaches that God arranged the events around Hagar and Ishmael so they would become a living example of a New Testament truth. Isaac was the son of promise, a picture of grace, while Ishmael was the son of the flesh, a picture of law. Paul's conclusion is that law and grace cannot live under the same roof, so legalism must be sent away just as Hagar and Ishmael were sent away.
Genesis 21:10 — Sarah's command to cast out Hagar and Ishmael is the exact event Paul quotes in Galatians 4:30 to illustrate the removal of law and legalism.
Galatians 4:22-23 — Paul directly states that Abraham had two sons, one born after the flesh and the other by promise, establishing the allegory.
Genesis 17:19 — God promises to establish His covenant through Isaac, not Ishmael, showing the covenant line of promise.
Scripture records that Abraham had two sons: Ishmael, born of Hagar the bondwoman, and Isaac, born of Sarah the freewoman. Genesis tells us that Sarah saw Ishmael mocking Isaac and declared, "Cast out this bondwoman and her son: for the son of this bondwoman shall not be heir with my son, even with Isaac" (Genesis 21:10). God confirmed Sarah's words, telling Abraham to listen to her voice, "for in Isaac shall thy seed be called" (Genesis 21:12). In Galatians, Paul draws on this history as an allegory: Abraham had two sons, "the one by a bondmaid, the other by a freewoman." The son of the bondwoman was born after the flesh, but the son of the freewoman was by promise (Galatians 4:22-23). Paul then applies the casting out of Hagar and Ishmael to the question of law versus grace: "Cast out the bondwoman and her son: for the son of the bondwoman shall not be heir with the son of the freewoman" (Galatians 4:30).
Les Feldick emphasizes that everything in the Old Testament was for our learning, and the account of Isaac and Ishmael is a clear example. He teaches that Ishmael was a child of the flesh and Isaac was a child of promise. Paul used this account in Galatians as an allegory: Ishmael represented the law, which is fleshly, while Isaac represented the age of grace, based on God's promises of redemption. Les also points out that God had an eternal purpose in the entire episode. Sarai originally wanted Hagar cast out, but God told her to return, because years later the situation would become a living example of a New Testament truth. When Ishmael mocked Isaac and could no longer live under the same roof, God told Abraham to send Hagar and Ishmael away. Paul used this to prove that law and legalism must be sent out, just as Ishmael was sent out. Les further connects the account to the modern Middle East conflict. Ishmael was Abraham's son, and the Arab world claims Abraham as their father. According to Les, the Koran places the covenant promises with Ishmael rather than Isaac, which is why many Arabs believe they are the rightful owners of the Holy Land. At the same time, God did not cast off Ishmael's descendants entirely, and the covenant was established with Isaac.
Paul's allegory in Galatians 4 is central to the New Testament connection. He says Abraham had two sons: one by a bondmaid, born after the flesh, and one by a freewoman, born by promise. Les Feldick teaches that Ishmael stood for law and legalism, while Isaac stood for grace. Paul then quotes the Genesis account of casting out the bondwoman and her son to show that legalism must be expelled.
Sarah saw Ishmael mocking Isaac and demanded that Hagar and Ishmael be cast out, saying that the son of the bondwoman would not be heir with Isaac. Les Feldick notes that Sarah was speaking God's truth, because the promised son was the one in whom the covenant would continue. God's command to Abraham was not cruelty but part of an eternal purpose, because Paul would later use the event as an allegory.
Les Feldick teaches that Ishmael was a child of Abraham, and this is the root of the ongoing conflict in the Middle East. The Arab world says they are the true children of Abraham because the Koran places the covenant promises with Ishmael rather than Isaac. As a result, they feel they are the rightful owners of the Holy Land. God chose Isaac for the covenant line, but He did not cast off Ishmael's people as nothing.
Paul writes that believers are the children of promise as Isaac was. Les Feldick explains that God promised Christ that a multitude of believers would be brought in as a result of the cross and resurrection. Just as Isaac was born through God's promise, those who are in Christ are children of promise. By contrast, Ishmael was born after the flesh and persecuted the one born after the Spirit, which Paul says is still true between the believing element and unbelievers.
Sarah's Demand to Cast Out the Bondwoman
Sarah demanded that Hagar and Ishmael be cast out because Ishmael was mocking Isaac, and Les emphasizes that she was speaking the very truth of God, since the promised son would continue the covenant.
God's Eternal Purpose in the Hagar Incident
God sent Hagar back to Sarah's tent earlier because the whole situation was destined to be a living example of a New Testament truth, showing that God was orchestrating history for a purpose.
The Allegory of Law versus Grace
Paul uses the allegory of Ishmael as the child of the flesh representing the law, and Isaac as the child of promise representing grace, and Paul quotes Genesis in Galatians 4:30.
Ishmael and the Arab Claim to Abraham
Ishmael was a natural son of Abraham, and the Arab world claims to be the true children of Abraham because the Koran assigns the covenant promises to Ishmael rather than Isaac.
Children of Promise and Persecution
As Isaac was, believers in Christ are children of promise, and the persecution of the flesh-born son against the Spirit-born son continues between the believing and the unbelieving elements.
God’s Foreknowledge vs. Free Will: How Salvation Works
Now then, if you'll come back to Genesis chapter 24, and you'll remember in our last few weeks of lessons we were dealing, of course, with Isaac and Ishmael, and how Isaac is by type a picture of grace. He was the son of promise, whereas Ishmael was the son of the flesh, and he was depicted by Paul in the book of Galatians as a picture of law.
Law and Grace Cannot Coexist
God sent Ishmael and Hagar out because Ishmael could not live under the same roof with the son of promise; Paul uses this to show that legalism must be sent out just as Ishmael was.
Covenant Established with Isaac
God told Abraham that Sarah would bear a son named Isaac and that He would establish His covenant not with Ishmael but with Isaac, yet He would not cast off Ishmael's people as nothing.
Genesis 21:10: Wherefore she said unto Abraham, Cast out this bondwoman and her son: for the son of this bondwoman shall not be heir with my son, even with Isaac.
This is the command Paul quotes in Galatians 4:30 as the basis for separating law and grace.
Genesis 21:12: And God said unto Abraham, Let it not be grievous in thy sight because of the lad, and because of thy bondwoman; in all that Sarah hath said unto thee, hearken unto her voice; for in Isaac shall thy seed be called.
God confirms that the promised seed would continue through Isaac, not Ishmael.
Genesis 17:19: And God said, Sarah thy wife shall bear thee a son indeed; and thou shalt call his name Isaac: and I will establish my covenant with him for an everlasting covenant, and with his seed after him.
God explicitly names Isaac as the one with whom His covenant would be established.
Galatians 4:22-23: For it is written, that Abraham had two sons, the one by a bondmaid, the other by a freewoman. But he who was of the bondwoman was born after the flesh; but he of the freewoman was by promise.
Paul introduces the allegory of the two sons as representing flesh and promise.
Galatians 4:28-30: Now we, brethren, as Isaac was, are the children of promise. But as then he that was born after the flesh persecuted him that was born after the Spirit, even so it is now. Nevertheless what saith the scripture? Cast out the bondwoman and her son: for the son of the bondwoman shall not be heir with the son of the freewoman.
Paul directly applies the Isaac and Ishmael account to believers and to the exclusion of legalism.
In Galatians 4, Paul identifies Ishmael as the son of the bondwoman born after the flesh, picturing the law, and Isaac as the son of promise, picturing grace. The allegory shows that the two cannot coexist; the bondwoman and her son must be cast out.
Sarah saw Ishmael mocking her son Isaac and declared that the son of the bondwoman would not share the inheritance with Isaac. Les Feldick points out that Sarah was speaking the truth of God, because the covenant promise continued through Isaac.
Les Feldick notes that the Arab world claims to be the true children of Abraham because the Koran places the covenant promises with Ishmael rather than Isaac. This is why many Arabs feel they are the rightful owners of the Holy Land.
Just as Isaac was born through God's promise, believers in Christ are children of promise. Les teaches that God promised Christ a multitude of believers as a result of the cross and resurrection, and these believers are seen in Isaac as the son of promise.
Watch the Teaching: Abraham, Sarah, and the Allegory of Law vs. Grace | Genesis 20-21