Which things are an allegory
Or "are allegorized": so Sarah and Hagar were allegorized by Philo the Jew F16, before they were by the apostle. Sarah he makes to signify virtue, and Hagar the whole circle of arts and sciences, which are, or should be, an handmaid to virtue; but these things respecting Hagar and Sarah, the bondwoman and the free, and their several offspring, are much better allegorized by the apostle here. An allegory is a way of speaking in which one thing is expressed by another, and is a continued metaphor; and the apostle's meaning is, that these things point at some other things; have another meaning in them, a mystical and spiritual one, besides the literal; and which the Jews call (vrdm) , "Midrash", a name they give to the mystical and allegorical sense of Scripture, in which they greatly indulge themselves. An allegory is properly a fictitious way of speaking; but here it designs an accommodation of a real history, and matter of fact, to other cases and things, and seems to intend a type or figure; and the sense to be, that these things which were literally true of Hagar and Sarah, of Ishmael and Isaac, were types and figures of things to come; just as what befell the Israelites were types and figures of things that would be under the Gospel dispensation, ( 1 Corinthians 10:11 )
for these are the two covenants,
or "testaments"; that is, these women, Hagar and Sarah, signify, and are figures of the two covenants; not the covenant of works, and the covenant of grace. Hagar was no figure of the covenant of works, that was made and broke before she was born; besides, the covenant she was a figure of was made at Mount Sinai, whereas the covenant of works was made in paradise: moreover, the covenant of works was made with Adam, and all his posterity, but the covenant which Hagar signified was only made with the children of Israel; she represented Jerusalem, that then was with her children. Nor was Sarah a figure of the covenant of grace, for this was made long before she had a being, even from everlasting; but they were figures of the two administrations of one and the same covenant, which were to take place in the world successively; and which following one the other, are by the author of the Epistle to the Hebrews called the first and the second, the old and the new covenants. Now these are the covenants or testaments, the old and the new, and the respective people under them, which were prefigured by these two women, and their offspring.
The one from the Mount Sinai;
that is, one of these covenants, or one of the administrations of the covenant, one dispensation of it, which is the first, and now called old, because abolished, took its rise from Mount Sinai, was delivered there by God to Moses, in order to be communicated to the people of Israel, who were to be under that form of administration until the coming of the Messiah. And because the whole Mosaic economy was given to Moses on Mount Sinai, it is said to be from thence: hence, in Jewish writings, we read, times without number, of (ynyom hvml hklh) , a rite, custom, constitution, or appointment given to Moses "from Mount Sinai", the same phrase as here. Sinai signifies "bushes", and has its name from the bushes which grew upon if, F17; in one of which the Lord appeared to Moses; for Horeb and Sinai are one and the same mount; one signifies waste and desolate, the other bushy; as one part of the mountain was barren and desert, and the other covered with bushes and brambles; and may fitly represent the condition of such that are under the law.
Which gendereth to bondage;
begets and brings persons into a state of bondage, induces on them a spirit of bondage to fear, and causes them to be all their lifetime subject to it; as even such were that were under the first covenant, or under the Old Testament dispensation:
which is Agar;
or this is the covenant, the administration of it, which Hagar, the bondwoman, Sarah's servant, represented.