9 And Sarah saw the son of Hagar the Egyptian, which she had borne unto Abraham, mocking.   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.   11 And the thing was very grievous in Abraham's sight because of his son.   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.   13 And also of the son of the bondwoman will I make a nation, because he is thy seed.

      The casting out of Ishmael is here considered of, and resolved on.

      I. Ishmael himself gave the occasion by some affronts he gave to Isaac his little brother, some think on the day that Abraham made the feast for joy that Isaac was safely weaned, which the Jews say was not till he was three years old, others say five. Sarah herself was an eye-witness of the abuse: she saw the son of the Egyptian mocking (v. 9), mocking Isaac, no doubt, for it is said, with reference to this (Gal. iv. 29), that he that was born after the flesh persecuted him that was born after the Spirit. Ishmael is here called the son of the Egyptian, because, as some think, the 400 years' affliction of the seed of Abraham by the Egyptians began now, and was to be dated hence, ch. xv. 13. She saw him playing with Isaac, so the LXX., and, in play, mocking him. Ishmael was fourteen years older than Isaac; and, when children are together, the elder should be careful and tender of the younger: but it argued a very base and sordid disposition in Ishmael to be abusive to a child that was no way a match for him. Note, 1. God takes notice of what children say and do in their play, and will reckon with them if they say or do amiss, though their parents do not. 2. Mocking is a great sin, and very provoking to God. 3. There is a rooted remaining enmity in the seed of the serpent against the seed of the woman. The children of promise must expect to be mocked. This is persecution, which those that will live godly must count upon. 4. None are rejected and cast out from God but those who have first deserved it. Ishmael is continued in Abraham's family till he becomes a disturbance, grief, and scandal to it.

      II. Sarah made the motion: Cast out this bond-woman, v. 10. This seems to be spoken in some heat, yet it is quoted (Gal. iv. 30) as if it had been spoken by a spirit of prophecy; and it is the sentence passed on all hypocrites and carnal people, though they have a place and a name in the visible church. All that are born after the flesh and not born again, that rest in the law and reject the gospel promise, shall certainly be cast out. It is made to point particularly at the rejection of the unbelieving Jews, who, though they were the seed of Abraham, yet, because they submitted not to the gospel covenant, were unchurched and disfranchised: and that which, above any thing, provoked God to cast them off was their mocking and persecuting the gospel church, God's Isaac, in its infancy, 1 Thess. ii. 16. Note, There are many who are familiarly conversant with the children of God in this world, and yet shall not partake with them in the inheritance of sons. Ishmael might be Isaac's play-fellow and school-fellow, yet not his fellow-heir.

      III. Abraham was averse to it: The thing was very grievous in Abraham's sight, v. 11. 1. It grieved him that Ishmael had given such a provocation. Note, Children ought to consider that the more their parents love them the more they are grieved at their misconduct, and particularly at their quarrels among themselves. 2. It grieved him that Sarah insisted upon such a punishment. "Might it not suffice to correct him? would nothing less serve than to expel him?" Note, Even the needful extremities which must be used with wicked and incorrigible children are very grievous to tender parents, who cannot thus afflict willingly.

      IV. God determined it, v. 12, 13. We may well suppose Abraham to be greatly agitated about this matter, loth to displease Sarah, and yet loth to expel Ishmael; in this difficulty God tells him what his will is, and then he is satisfied. Note, A good man desires no more in doubtful cases than to know his duty, and what God would have him do; and, when he is clear in this, he is, or should be, easy. To make Abraham so, God sets this matter before him in a true light, and shows him, 1. That the casting out of Ishmael was necessary to the establishment of Isaac in the rights and privileges of the covenant: In Isaac shall thy seed be called. Both Christ and the church must descend from Abraham through the loins of Isaac; this is the entail of the promise upon Isaac, and is quoted by the apostle (Rom. ix. 7) to show that not all who come from Abraham's loins were the heirs of Abraham's covenant. Isaac, the promised son, must be the father of the promised seed; therefore, "Away with Ishmael, send him far enough, lest he corrupt the manners or attempt to invade the rights of Isaac." It will be his security to have his rival banished. The covenant seed of Abraham must be a peculiar people, a people by themselves, from the very first, distinguished, not mingled with those that were out of covenant; for this reason Ishmael must be separated. Abraham was called alone, and so must Isaac be. See Isa. li. 2. It is probable that Sarah little thought of this (John xi. 51), but God took what she said, and turned it into an oracle, as afterwards, ch. xxvii. 10. 2. That the casting out of Ishmael should not be his ruin, v. 13. He shall be a nation, because he is thy seed. We are not sure that it was his eternal ruin. It is presumption to say that all those who are left out of the external dispensation from all his mercies: those may be saved who are not thus honoured. However, we are sure it was not his temporal ruin. Though he was chased out of the church, he was not chased out of the world. I will make him a nation. Note, (1.) Nations are of God's making: he founds them, he forms them, he fixes them. (2.) Many are full of the blessings of God's providence that are strangers to the blessings of his covenant. (3.) The children of this world often fare the better, as to outward things, for their relation to the children of God.

      21 Tell me, ye that desire to be under the law, do ye not hear the law?   22 For it is written, that Abraham had two sons, the one by a bondmaid, the other by a freewoman.   23 But he who was of the bondwoman was born after the flesh; but he of the freewoman was by promise.   24 Which things are an allegory: for these are the two covenants; the one from the mount Sinai, which gendereth to bondage, which is Agar.   25 For this Agar is mount Sinai in Arabia, and answereth to Jerusalem which now is, and is in bondage with her children.   26 But Jerusalem which is above is free, which is the mother of us all.   27 For it is written, Rejoice, thou barren that bearest not; break forth and cry, thou that travailest not: for the desolate hath many more children than she which hath a husband.   28 Now we, brethren, as Isaac was, are the children of promise.   29 But as then he that was born after the flesh persecuted him that was born after the Spirit, even so it is now.   30 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.   31 So then, brethren, we are not children of the bondwoman, but of the free.

      In these verses the apostle illustrates the difference between believers who rested in Christ only and those judaizers who trusted in the law, by a comparison taken from the story of Isaac and Ishmael. This he introduces in such a manner as was proper to strike and impress their minds, and to convince them of their great weakness in departing from the truth, and suffering themselves to be deprived of the liberty of the gospel: Tell me, says he, you that desire to be under the law, do you not hear the law? He takes it for granted that they did hear the law, for among the Jews it was wont to be read in their public assemblies every sabbath day; and, since they were so very fond of being under it, he would have them duly to consider what is written therein (referring to what is recorded Gen. xvi. and xxi.), for, if they would do this, they might soon see how little reason they had to trust in it. And here, 1. He sets before them the history itself (v. 22, 23): For it is written, Abraham had two sons, &c. Here he represents the different state and condition of these two sons of Abraham--that the one, Ishmael, was by a bond-maid, and the other, Isaac, by a free-woman; and that whereas the former was born after the flesh, or by the ordinary course of nature, the other was by promise, when in the course of nature there was no reason to expect that Sarah should have a son. 2. He acquaints them with the meaning and design of this history, or the use which he intended to make of it (v. 24-27): These things, says he, are an allegory, wherein, besides the literal and historical sense of the words, the Spirit of God might design to signify something further to us, and that was, That these two, Agar and Sarah, are the two covenants, or were intended to typify and prefigure the two different dispensations of the covenant. The former, Agar, represented that which was given from mount Sinai, and which gendereth to bondage, which, though it was a dispensation of grace, yet, in comparison of the gospel state, was a dispensation of bondage, and became more so to the Jews, through their mistake of the design of it, and expecting to be justified by the works of it. For this Agar is mount Sinai in Arabia (mount Sinai was then called Agar by the Arabians), and it answereth to Jerusalem which now is, and is in bondage with her children; that is, it justly represents the present state of the Jews, who, continuing in their infidelity and adhering to that covenant, are still in bondage with their children. But the other, Sarah, was intended to prefigure Jerusalem which is above, or the state of Christians under the new and better dispensation of the covenant, which is free both from the curse of the moral and the bondage of the ceremonial law, and is the mother of us all--a state into which all, both Jews and Gentiles, are admitted, upon their believing in Christ. And to this greater freedom and enlargement of the church under the gospel dispensation, which was typified by Sarah the mother of the promised seed, the apostle refers that of the prophet, Isa. liv. 1, where it is written, Rejoice, thou barren that bearest not; break forth and cry, thou that travailest not; for the desolate hath many more children than she who hath a husband. 3. He applies the history thus explained to the present case (v. 28); Now we, brethren, says he, as Isaac was, are the children of the promise. We Christians, who have accepted Christ, and rely upon him, and look for justification and salvation by him alone, as hereby we become the spiritual, though we are not the natural, seed of Abraham, so we are entitled to the promised inheritance and interested in the blessings of it. But lest these Christians should be stumbled at the opposition they might meet with from the Jews, who were so tenacious of their law as to be ready to persecute those who would not submit to it, he tells them that this was no more than what was pointed to in the type; for as then he that was born after the flesh persecuted him that was born after the Spirit, they must expect it would be so now. But, for their comfort in this case, he desires them to consider what the scripture saith (Gen. xxi. 10), Cast out the bond-woman and her son, for the son of the bond-woman shall not be heir with the son of the free-woman. Though the judaizers should persecute and hate them, yet the issue would be that Judaism would sink, and wither, and perish; but true Christianity should flourish and last for ever. And then, as a general inference from the whole of the sum of what he had said, he concludes (v. 31), So then, brethren, we are not children of the bond-woman, but of the free.