(22) For.--This particle would naturally not be expressed in English. It was a reason for the question which had been asked just before: "For the Law does supply a case in point."

The one by a bondmaid.--Hagar, it seems from Genesis 16:1, was an Egyptian. The word for "bondmaid" was not confined to this sense in earlier Greek, but was used for any young girl.

Verse 22 - For it is written (γέγραπται γάρ); for the Scripture saith. The phrase does not here, as it does usually, introduce the citation of a text, but prefaces a brief summary of facts; these facts being recited in words gathered out of the Septuagint Version of Genesis 16. and 21, in much the same way as the story of Melchisedec is sketched in Hebrews 7:1-4. That Abraham had two sons (ὅτι Ἀβραὰμ δύο υἱοὺς ἔσχεν); that Abraham had gotten two sons; for ἔσχεν is not exactly equivalent to εϊχεν. Attention has been drawn to other sons born of Keturah (Genesis 25:1, 2), who both in ancient and in modern days (see Windisch-mann) have been very plausibly interpreted as analogously pointing forward allegorically to those heretical bodies, now vanished, which threatened such danger to the Church in the first centuries. But the apostle's concern here is exclusively with the posture of affairs subsisting at the time of Hagar's and Ishmael's expulsion from the patriarch's family, quoted in ver. 30 from Genesis 21. Even if he had seen fit by allegorical exposition to apply Scripture to those dire forms of utterly perverted Christianity, which he certainly did look forward to as about to arise, it is very questionable whether he would have conceded to them so venerable a parentage as having Abraham for their forefather. Mosaism in its place was a thing of Divine origin, even as Christianity itself was, both of them "covenants" of God; not so the monstrous forms of Gnostic and Manichean teaching which horrified the primitive Church. In fact, typology, that is to say, the interpretation of Old Testament Scripture as bearing a designed allegorical sense, requires very cautious handling. The tracing of analogies is an interesting and pleasing exercise of theological ingenuity; but it is one thing to trace a parallelism, and a quite different thing to detect a latent predictive sense intended by the Holy Spirit. The one by a bondmaid (e%na e)k th = paidi/skh); one by the handmaid; the expression pointing to the individual mother known from the sacred history. The word παιδίσκη in classical Greek means a girl either slave or free. In the Septuagint it is generally a slave (not, however, in Ruth 4:12, where it renders the Hebrew na'arah); in the New Testament it is always a maidservant. St. Paul borrows the word from the Septuagint of Genesis 15. and 21, where it renders the Hebrew shiphehah. Hagar was the personal property of Sarah. The other by a freewoman (καὶ ἕνα ἐκ τῆς ἐλευθέρας); and one by the freewoman. The word "freewoman" is never applied to Sarah in the story in Genesis; not even in the passage freely quoted in ver. 30; but it was an obviously true description, and with perfect fairness introduced in antithesis to Hagar. As applied to one holding so princessly a position in the story as Sarah, the idea of a freewoman stands coloured with a deep tincture of dignity.

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.For it is written,.... In Genesis 16:15

that Abraham had two sons, not two sons only; for besides the two referred to, he had six more, Genesis 25:2 but it being only pertinent to the apostle's purpose to take notice of these two, he mentions no more, though he does not deny that he had any more. These two sons were Ishmael and Isaac:

the one by a bondmaid. Ishmael was by Hagar, Sarah's servant, who represented the covenant the Jewish nation was under the bondage of.

The other by a free woman. Isaac was by Sarah, Abraham's proper and lawful wife, who was mistress of the family, and represented in figure the covenant, and Gospel church state, and all believers, Gentiles as well as Jews, as under the liberty thereof.