Galatians 4:28 - Joseph Benson’s Commentary on the Old and New Testaments

Now That I may apply what has just been advanced to ourselves; we, brethren Who believe, whether Jews or Gentiles; as Isaac was Κατα Ισαακ, after the manner of Isaac; are children of promise Are children of God, being children of Abraham and Sarah, by the promise which made him the father, and her the mother, of nations. In other words, we are children, not born in a natural way, but by the supernatural power of God; and as such, we are heirs of the promise made to believing Abraham. And, “if believers, after the manner of Isaac, are children begotten to Abraham by the divine power accompanying the promise, can it be doubted that they were typified by Isaac, and that his procreation was deferred till the bodies of his parents were dead as to these things, that being supernaturally begotten, he might be a fit type of those who by divine power become the seed of Abraham, through faith.” But Indeed the parallel holds further still; for as then, he that was born after the flesh That is, Ishmael, in whose production there was nothing beyond the common course of nature, and who was related to Abraham by natural descent only; persecuted him who was born after the Spirit That is, Isaac, who was produced by the special energy of God's miraculous power; even so it is now The carnal Jews, who are the seed of Abraham after the flesh, abuse and persecute us who believe in Christ, and are therefore Abraham's seed after the Spirit. Ishmael's persecution of Isaac consisted in his mocking at the feast of his weaning, Genesis 21:9. “No doubt he pretended that by right of primogeniture he was his father's heir, and therefore he ridiculed the feast made in honour of Isaac as the heir, together with Sarah's laying claim to the whole of the inheritance for her son. This action was typical of the contempt with which the Jews, Abraham's natural posterity, would treat his spiritual seed, and their hopes of salvation through faith; typical also of the claim which the natural seed would set up, of being the only heirs of God, because they were first his people.” But what saith the Scripture Showing the consequence of this? Cast out the bond-woman and her son Who mocked Isaac. Which sentence, however grievous it might be to Abraham, when pronounced by Sarah, God confirmed, and they were cast out of Abraham's family. And so, as the apostle's discourse implies, shall all who reject Christ, and seek justification and salvation by the law of Moses, notwithstanding their boasted descent from Abraham, be cast out of the church and family of God, and rejected from being his people; especially if they persecute them who are his children by faith; and they shall not be permitted to be heirs of his promise with them. So that, as in his birth and condition, his character and actions; so likewise in his being cast out of his father's house, Ishmael was a fit type of the unbelieving and disobedient Jews. So then To sum up all; we Who believe; are not the children of the bond-woman Are not under subjection to the servile dispensation of the law, nor have any thing to do with it; but we are children of the free-woman And have the privilege of being called into a state of liberty under the spiritual covenant of the gospel, being free from the curse and bond of the law, and from the power of sin and Satan.