22 For it is written, that Abraham had two sons, one by the handmaid, and one by the freewoman. 23 Howbeit the [son] by the handmaid is born after the flesh; but the [son] by the freewoman [is born] through promise. 24 Which things contain an allegory: for these [women] are two covenants; one from mount Sinai, bearing children unto bondage, which is Hagar. 25 Now this Hagar is mount Sinai in Arabia and answereth to the Jerusalem that now is: for she is in bondage with her children. 26 But the Jerusalem that is above is free, which is our mother. 27 For it is written, Rejoice, thou barren that bearest not; Break forth and cry, thou that travailest not: For more are the children of the desolate than of her that hath the husband. 28 Now we, brethren, as Isaac was, are children of promise. 29 But as then he that was born after the flesh persecuted him [that was born] after the Spirit, so also it is now. 30 Howbeit what saith the scripture? Cast out the handmaid and her son: for the son of the handmaid shall not inherit with the son of the freewoman.
Matthew Henry's Commentary on Galatians 4:22-30
Commentary on Galatians 4:21-27
(Read Galatians 4:21-27)
The difference between believers who rested in Christ only, and those who trusted in the law, is explained by the histories of Isaac and Ishmael. These things are an allegory, wherein, beside the literal and historical sense of the words, the Spirit of God points out something further. Hagar and Sarah were apt emblems of the two different dispensations of the covenant. The heavenly Jerusalem, the true church from above, represented by Sarah, is in a state of freedom, and is the mother of all believers, who are born of the Holy Spirit. They were by regeneration and true faith, made a part of the true seed of Abraham, according to the promise made to him.
Commentary on Galatians 4:28-31
(Read Galatians 4:28-31)
The history thus explained is applied. So then, brethren, we are not children of the bond-woman, but of the free. If the privileges of all believers were so great, according to the new covenant, how absurd for the Gentile converts to be under that law, which could not deliver the unbelieving Jews from bondage or condemnation! We should not have found out this allegory in the history of Sarah and Hagar, if it had not been shown to us, yet we cannot doubt it was intended by the Holy Spirit. It is an explanation of the subject, not an argument in proof of it. The two covenants of works and grace, and legal and evangelical professors, are shadowed forth. Works and fruits brought forth in a man's own strength, are legal. But if arising from faith in Christ, they are evangelical. The first covenant spirit is of bondage unto sin and death. The second covenant spirit is of liberty and freedom; not liberty to sin, but in and unto duty. The first is a spirit of persecution; the second is a spirit of love. Let those professors look to it, who have a violent, harsh, imposing spirit, towards the people of God. Yet as Abraham turned aside to Hagar, so it is possible a believer may turn aside in some things to the covenant of works, when through unbelief and neglect of the promise he acts according to the law, in his own strength; or in a way of violence, not of love, towards the brethren. Yet it is not his way, not his spirit to do so; hence he is never at rest, till he returns to his dependence on Christ again. Let us rest our souls on the Scriptures, and by a gospel hope and cheerful obedience, show that our conversation and treasure are indeed in heaven.