But what saith the Scripture? There was some consolation in knowing that we do but share the lot of our father Isaac; but it is a still greater consolation, when he adds, that hypocrites, with all their boasting, can gain nothing more than to be cast out of the spiritual family of Abraham; and that, to whatever extent they may harass us for a time, the inheritance will certainly be ours. Let believers cheer themselves with this consolation, that the tyranny of the Ishmaelites will not last for ever. They appear to have reached the highest pre-eminence, and, proud of their birthright, look down upon us with contempt; but they will one day be declared to be the descendants of Hagar, the sons of a slave, and unworthy of the inheritance. Let us be instructed by this beautiful passage, "not to fret ourselves because of evil-doers, neither be envious against the workers of iniquity," (Psalm 37:1,) when they hold a temporary habitation and rank in the Church, but patiently to look for the end which awaits them. There are many pretended Christians, or strangers, who hold a place in the Church, but who afterwards give evidence of their departure from the faith, as he who, proud of his birthright, at first reigned, was cast out like a foreigner with the posterity of Ishmael. Some censorious persons smile at Paul's simplicity, in comparing a woman's passion, arising out of a trifling quarrel, to a judgment of God. But they overlook the decree of God, which took effect in such a manner, as to make it manifest that the whole transaction was directed by a heavenly providence. That Abraham should have been commanded to humor his wife (Genesis 21:12) entirely in the matter, is no doubt extraordinary, but proves that God employed the services of Sarah for confirming his own promise. In a word, the casting out of Ishmael was nothing else than the consequence and the accomplishment of that promise, "In Isaac shall thy seed be called," (Genesis 21:12,) -- not in Ishmael. Although, therefore, it was the revenging of a woman's quarrel, yet God did not the less make known his sentence by her mouth as a type of the Church.

Nevertheless - But Ἀλλὰ (Alla).
What saith the Scripture? - What does the Scripture teach on the subject? What lesson does it convey in regard to the bondman?
Cast out the bondwoman and her son - This was the language of Sarah, in an address to Abraham, requesting him to cast out Hagar and Ishmael; Genesis 21:10. That was done. Paul uses it here as applicable to the case before him. As used by him the meaning is, that everything like servitude in the gospel is to be rejected, as Hagar and Ishmael were driven away. It does not mean, as it seems to me, that they were to expel the Jewish teachers in Galatia, but that they were to reject everything like servitude and bondage; they were to adhere only to that which was free. Paul cannot here mean that the passage in Genesis 21:10, originally had reference to the gospel, for nothing evidently was further from the mind of Sarah than any such reference; nor can it be shown that he meant to approve of or vindicate the conduct of Sarah; but he finds a passage applicable to his purpose, and he conveys his ideas in that language as exactly expressing his meaning. We all use language in that way wherever we find it.
(Yet God confirmed the sentence of Sarah; Genesis 21:12. Hence, Mr. Scott thus paraphrases, "But as the Galatians might read in the Scriptures that God himself had commanded Hagar and Ishmael to be sent away from Abraham's family, that the son of the bondwoman might not share the inheritance with Isaac; even so the Jewish nation would soon be cast out of the church, and all who continued under the legal covenant excluded from heaven."

What saith the Scripture? - (In Genesis 21:10): Cast out the bond woman and her son: and what does this imply in the present case? Why, that the present Jerusalem and her children shall be cast out of the favor of God, and shall not be heirs with the son of the free woman - shall not inherit the blessings promised to Abraham, because they believe not in the promised seed.

Nevertheless, what saith the Scripture?.... This is a Talmudic form of citing Scriptures, and answers to , "what says the Scriptures (e)?" the passage referred to is Genesis 21:10 and which are the words of Sarah to Abraham; but inasmuch as she spake them under divine inspiration, and they were approved of and confirmed by God, as appears from Genesis 21:12 they are ascribed to God speaking in the Scripture:
cast out the bondwoman and her son, for the son of the bondwoman shall not be heir with the son of the free woman. There is very little difference in the citation from the original. The apostle omits the word "this" in both clauses, which though very proper to be expressed by Sarah, to point out the person she meant, and as being in a vehement passion, was not absolutely necessary to be retained by the apostle, since by the context there is no difficulty of knowing who is meant by her; though the Alexandrian copy has the word in it: and instead of "with my son, with Isaac", the apostle says, "with the son of the free woman, Sarah"; there speaking of herself, whose character the apostle gives, in opposition to the bondwoman: in like manner a Jewish writer (f) reads and interprets it,
"for the son of this woman shall not be heir , "with the son of the mistress".''
The casting of Hagar and Ishmael out of Abraham's family was a type and emblem of the rejection of the carnal and self-righteous Jews from the Gospel church state; nor ought any carnal persons, any that are after the flesh, unregenerate ones, or that trust to their own righteousness, to be in a Gospel church; as they will also be excluded and thrust out of the kingdom of heaven, into which no unregenerate and unrighteous, or self-righteous persons shall enter. The Jews make this ejection of Hagar and her son to be both out of this world and that which is to come (g). The reason given why the one should not be heir with the other perfectly agrees with the Jewish canons; which was not because he was the son of a concubine, for the sons of concubines might inherit, if they were Israelites, and free, but because he was the son of a bondwoman, for thus they run (h);
"all that are near of kin, though by iniquity, are heirs, as they that are legitimate; how? thus for instance, if a man has a son that is spurious, or a brother that is spurious, lo, these are as the other sons, and the other brethren for inheritance; but if, , "his son is by an handmaid", or by a strange woman, he is no son in any of these matters, , "and no heir at all":''
and again (i),
"an Israelite that hath a son by an handmaid, or by a Gentile, seeing he is not called his son, he that he has after him by an Israelitish woman, , "is the firstborn for inheritance", and takes the double portion.''
The reason assigned for non-inheritance in the text implies that the children of the free woman, the spiritual seed of Abraham, shall inherit the privileges of God's house, the blessings of grace, and eternal glory; they are children of the promise, and heirs according to it; when the children of the bondwoman, self-righteous ones, shall not; for the inheritance is not of the law, neither are they heirs who are of the works of it; nor is it to be enjoyed by mixing the law and Gospel, grace and works, in the business of salvation.
(e) T. Bab. Beracot, fol. 9. 2. (f) R. Abraham Seba, Tzeror, fol. 21. 3. (g) Pirke Eliezer, c. 30. (h) Maimon. Hilch. Nechalot, c. 1. sect. 7. (i) Ib c. 2. sect. 12.

Genesis 21:10, Genesis 21:12, where Sarah's words are, "shall not be heir with my son, even with Isaac." But what was there said literally, is here by inspiration expressed in its allegorical spiritual import, applying to the New Testament believer, who is antitypically "the son of the free woman." In John 8:35-36, Jesus refers to this.
Cast out--from the house and inheritance: literally, Ishmael; spiritually, the carnal and legalists.
shall not be heir--The Greek is stronger, "must not be heir," or "inherit."

But what saith the scripture - Showing the consequence of this. Cast out the bondwoman and her son - Who mocked Isaac. In like manner will God cast out all who seek to be justified by the law; especially if they persecute them who are his children by faith. Genesis 21:10.