That will not, indeed, prove them all to have been the people of God in the sense before given, for the reason here adduced by our author.
Howbeit, the preface to the ten commandments deserves a particular notice, in the matter, of the Sinai transaction, Exod. 20:2, “I am the Lord thy God, which have brought thee out of the land of Egypt, out of the house of bondage.” Hence it is evident to me, that the covenant of grace was delivered to the Israelites on Mount Sinai. For the Son of God, the messenger of the covenant of grace, spoke these words to a select people, the natural seed of Abraham, typical of his whole spiritual seed. He avoucheth himself to be their God; namely, in virtue of the promise, or covenant made with Abraham, Gen. 17:7, “I will establish my covenant—to be a God unto thee, and to thy seed after thee: and their God, which brought them out of the land of Egypt; according to the promise made to Abraham at the most solemn renewal of the covenant with him, Gen. 15:14, “Afterward shall they come out with great substance.” And he first declares himself their God, and then requires obedience, according to the manner of the covenant with Abraham, Gen. 17:1, “I am the Almighty God (i. e. in the language of the covenant, The almighty God to thee, to make thee for ever blessed through the promised seed) walk thou before me, and be thou perfect.”
But that the covenant of works was also, for special ends, repeated and delivered to the Israelites on Mount Sinai, I cannot refuse, 1. Because of the apostle’s testimony, Gal. 4:24, “These are the two covenants; the one from Mount Sinai, which gendereth to bondage.” For the children of this Sinai covenant the apostle here treats of, are excluded from the eternal inheritance, as Ishmael was from Canaan, the type of it, ver. 30, “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;” but this could never be said of the children of the covenant of grace under any dispensation, though both the law and covenant from Sinai itself, and its children, were even before the coming of Christ under a sentence of exclusion, to be execute on them respectively in due time. 2. The nature of the covenant of works is most expressly in the New Testament brought in, propounded, end explained, from the Mosaical dispensation. The commands of it from Exod. 20 by our blessed Saviour, Matth. 19:17–19, “If thou wilt enter into life, keep the commandments. He saith onto him, Which? Jesus said, Thou shalt do no murder, thou shalt not commit adultery,” &c. The promise of it, Rom. 10:5, “Moses describes the righteousness which is of the law, that the man which doth these things shall live by them.” The commands and promise of it together, see Luke 10:25–28. The terrible sanction of it. Gal. 3:10, “For it is written, (viz. Deut. 27:26,) Cursed is every one that continueth not in all things which are written in the book of the law to do them.” 3. To this may be added the opposition betwixt the law and grace so frequently inculcated in the New Testament, especially in Paul’s epistles. See one text for all, Gal. 3:12, “And the law is not of faith, but the man that doeth them shall live in them.” 4. The law from Mount Sinai was a covenant, Gal. 4:24, “These are the two covenants, the one from the Mount Sinai;” and such a covenant as had a semblance of disannuling the covenant of grace, Gal. 3:17, “The covenant that was confirmed before of God in Christ, the law which was 430 years after, cannot disannul;” yea, such a one as did, in his own nature, bear a method of obtaining the inheritance, so far different from that of the promise, that it was inconsistent with it; “For if the inheritance be of the law, it is no more of promise,” Gal. 3:18, wherefore the covenant of the law from Mount Sinai could not be the covenant of grace, unless one will make this last not only a covenant seeming to destroy itself, but really inconsistent; but it was the covenant of works, which indeed had such a semblance, and in its own nature did bear such a method as before noted; howbeit, as Ainsworth says, “The covenant of the law now given could not disannul the covenant of grace.” Gal. 3:17.—Annot. on Exod. 19:1.
Wherefore I conceive the two covenants to have been both delivered on Mount Sinai to the Israelites. First, The covenant of grace made with Abraham, contained in the preface, repeated and promulgate there unto Israel, to be believed and embraced by faith, that they might be saved; to which were annexed the ten commandments, given by the Mediator Christ, the head of the covenant, as a rule of life to his covenant people. Secondly, The covenant of works made with Adam, contained in the same ten commands, delivered with thunderings and lightnings, the meaning of which was afterwards cleared by Moses, describing the righteousness of the law and sanction thereof, repeated and promulgate to the Israelites there, as the original perfect rule of righteousness, to be obeyed; and yet were they no more bound hereby to seek righteousness by the law than the young man was by our Saviour’s saying to him, Mat. 19:17, 18, “If thou wilt enter into life, keep the commandments—Thou shalt do no murder,” &c. The latter was a repetition of the former.
Thus there is no confounding of the two covenants of grace and works; but the latter was added to the former as subservient unto it, to turn their eyes towards the promise, or covenant of grace: “God gave it to Abraham by promise. Wherefore then serveth the law? it was added, because of transgressions, till the Seed should come,” Gal. 3:18, 19. So it was unto the promise given to Abraham, that this subservient covenant was added; and that promise we have found in the preface to the ten commands. To it, then, was the subservient covenant, according to the apostle, added, put, or set to, as the word properly signifies. So that it was no part of the covenant of grace, the which was entire to the fathers, before the time that it was set to it; and yet in, to the New Testament church, after that it is taken away from it: for, says the apostle, “It was added till the Seed should come.” Hence it appears, that the covenant of grace was, both in itself, and in God’s intention, the principal part of the Sinai transaction: nevertheless the covenant of works was the most conspicuous part of it, and lay most open to the view of the people.
According to this account of the Sinai transaction, the ten commands, there delivered, must come under a twofold notion or consideration; namely, as the law of Christ, and as the law of works: and this is not strange, if it is considered, that they were twice written on tables of stone, by the Lord himself,—the first tables the work of God, Exod. 32:16, which were broken in pieces, verse 19, called the tables of the covenant, Deut 9:11, 15,—the second tables the work of Moses, the typical Mediator, Exod. 34:1; deposited at first (it would seem) in the tabernacle, mentioned chap, 33:7, afterward, at the rearing of the tabernacle with all its furniture, laid up in the ark within the tabernacle, chap. 25:16; and whether or not some such thing is intimated, by the double accentuation of the decalogue, let the learned determine; but to the ocular inspection it is evident, that the preface to the ten commands, Exod. 20:2, and Deut. 5:6, stands in the original, both as a part of a sentence joined to the first command, and also as an entire sentence separated from it, and shut up by itself.
Upon the whole, one may compare with this the first promulgation of the covenant of grace, by the messenger of the covenant in paradise, Gen. 3:15, and the flaming sword placed there by the same hand, “turning every way to keep the way of the Tree of Life.”
Boston, Works, 7.197
(Boston’s Note on the Marrow of Modern Divinity)