In the Hebrew, the word covenant is not expressed. The text runs only thus, we make a sure one, or a sure thing. Covenants are in their own nature and constitution, things of so much certainty and assurance, that by way of excellency, a covenant is called, a sure one, or an assurance. When a sure one is but named, a covenant must be understood. As, the "Holy One" is God, and the "Holy One and the Just," is Christ. You may know whom the Holy Ghost means, when He saith "The Holy One and the Just." So the sure one, is a covenant. You may know what they made, when the Holy Ghost saith, they made a sure one. Hence observe, that
A well grounded covenant is a sure, a firm, and an irrevocable act. When you have such an all this, (and such you have) as is here concentrated in the text, to lay into, or for the foundation of a covenant, the superstruction is æternitati sacrum, and must stand for ever.
A weak ground is but a weak obligation; and a sinful ground is no obligation. There is much sin in making a covenant upon sinful grounds, and there is more sin in keeping of it. But when the preservation of true religion, and the vindication of just liberties meet in the groundwork, ye may swear and not repent; yea, if ye swear, ye must not repent. For because of all such things as these, we ought (if we make any, and that we ought) to make a sure covenant.
The covenant God makes with man is a sure covenant. Hence called a "Covenant of salt," because salt preserves from perishing and putrefaction. The covenant of God with man about temporal things, is called a "Covenant of Salt, and a covenant forever." For tho' His covenant about temporal things (as all temporals must) hath an end of termination, yet it hath no end of corruption: time will conclude it, but time cannot violate it. But as for His covenant about eternal things, that, like eternity, knows not only no end of corruption, but none of termination. "Altho' my house (saith gasping David) be not so with God; yet He hath made with me an everlasting covenant, ordered in all things and sure: for this is all my salvation, and all my desire, altho' He make it not to grow." And what is it that makes the covenant of God with man thus sure? sure not only in itself, but (as the apostle speaks) to all the seed. Is it not this, because it hath a strong foundation, a double, impregnable foundation? First, His own free grace. Second, The blood of Christ; which is therefore also called, the blood of the covenant. Because of all this, this all, which hath an infinity in it, the Lord God hath made with us a sure covenant.
Now, as the stability and everlastingness of God's covenant with His elect, lies in the strength of the foundation, "His own love, and the blood of His Son:" so the stability and firmness of our covenant with God, lies in the strength of this foundation, the securing of the gospel, and the asserting of gospel-purity in worship, and privileges in government; the securing of our lives, and the asserting of our common liberties. When at any time ye can question, and, from the oracles of truth, be resolved, that these are sufficient grounds of making a covenant, or that these are not ours, ye may go, and unassure the covenant which ye make this day.
Application. Let me therefore invite you in the words of the prophet Jeremiah, "Come let us join ourselves to the Lord, in a perpetual covenant that shall never be forgotten." And do not these look like the days wherein the prophet calls to the doing of this? "In those days, and at that time, saith the Lord." What time, and what days were those? the beginning of the chapter answers. "The word that the Lord spake against Babylon, declare ye among the nations, and publish, and set up a standard, publish and conceal not: say, Babylon is taken, Bell is confounded, Merodach is broken in pieces; her idols are confounded, her images are broken in pieces: for out of the north there cometh up a nation against her, which shall make her land desolate." Then follows, "In those days and at that time saith the Lord, the children of Israel shall come. And they shall ask the way to Zion, with their faces thitherward saying, Come, and let us join ourselves to the Lord, in a perpetual covenant that shall not be forgotten."
Are not these the days, and this the time (I speak not of time to a day, but of time and days) wherein the Lord speaks against Babylon, and against the land of the Chaldeans: wherein He saith, "Declare among the nations, and publish, and set up the standard." Are not these the days, and this the time, when out of the north there cometh up a nation against her? As face answers face in the water, so do the events of these days answer, if not the letter, yet much of the mystery of this prophecy. There seems wanting only the work which this day is bringing forth, and a few days more (I hope) will bring unto perfection, the joining of ourselves in a perpetual covenant, never to be forgotten. It is very observable, how the prophet, as it were, with one breath saith, "Babylon is taken." And, "Come let us join ourselves in covenant." As if there were no more in it but this, take the covenant, and ye take Babylon. Or, as if the taking of a covenant were the ready way, the readiest way to take Babylon. Surely at the report of the taking of this sure covenant, we in our prayer-visions (as the prophet Habakkuk), "May see the tents of Cushan in affliction, and the curtains of the land of Midian tremble." Or, as Moses in his triumphant song, "The people shall hear, and be afraid: sorrow shall take hold of the inhabitants of Palestina. The dukes of Edom shall be amazed; the mighty men of Moab, trembling shall take hold upon them; the inhabitants of Canaan (who are now the inhabitants of Babylon) shall melt away. The towers of Babylon shall quake, and her seven hills will move. The great mountain before our Zerubbabel, will become a plain, and we shall bring forth the head-stone (of our reformation) with shouting, crying, grace, grace unto it." Why may we not promise to ourselves such glorious effects (and not build these castles in the air) when we have laid so promising a foundation, this sure covenant, and have made a perpetual covenant, never to be forgotten?
The three things I shall propose, which this covenant will bring in, as facilitating contributions to so great a work:
1. This covenant will distinguish men, and separate the precious from the vile. In the twentieth chapter of Ezekiel, the Lord promiseth His people, after this manner, "I will cause you to pass under the rod, and I will bring you into the bond of the covenant." The phrase of causing to pass under the rod, is an allusion to shepherds, or the keepers of cattle, who when they would take special notice of their sheep or cattle, either in their number to tithe them, or in their goodness to try them, they brought them into a fold, or some other inclosed place, when letting them pass out at a narrow door, one by one, they held a rod over them, to count or consider more distinctly of them. This action was called a "passing of them under the rod," as Moses teaches us, "And concerning the tithe of the herd, or of the flock, even of whatsoever passeth under the rod, the tenth shall be holy unto the Lord." The learned Junius expounds that text in Ezekiel by this in Leviticus, giving the sense thus, "As if the Lord had said, I will prove and try the whole people of Israel, as a shepherd doeth his flock, that I may take the good and sound into the fold of My covenant, and cast out the wicked and unsound." Which interpretation is not only favoured, but fully approved, in the words immediately following, "I will bring you into the bond of the covenant, and I will purge out from among you the rebels, and them that transgress against Me."
A covenant is to a nation, as a fan to the floor, which purges away the chaff and purifies the wheat. It is like the furnace to the metal, which takes away the dross and shews you a refined lump. It is a Shibboleth, to distinguish Ephraimites from Gileadites. And who knows not how great an advantage it is for the successful carrying on of any honourable design, to know friends from enemies, and the faithful from false brethren? Some have thought it unpolitical to set-a-foot this covenant, lest it should discover more enemies than friends, and so holding out to the view more than otherwise can be seen, the weakness of a party may render them, not only more obnoxious, but more inconsiderable.