15. I speak after the manner of men. By this expression he intended to put them to the blush. It is highly disgraceful and base that the testimony of God should have less weight with us than that of a mortal man. In demanding that the sacred covenant of God shall receive not less deference than is commonly yielded to ordinary human transactions, he does not place God on a level with men. The immense distance between God and men is still left for their consideration.
Though it be but a man’s covenant. This is an argument from the less to the greater. Human contracts are admitted on all hands to be binding: how much more what God has established? The Greek word διαθήκη, here used, signifies more frequently, what the Latin versions here render it, ( testamentum,) a testament; but sometimes too, a covenant, though in this latter sense the plural number is more generally employed. It is of little importance to the present passage, whether you explain it covenant or testament. The case is different with the Epistle to the Hebrews, where the apostle unquestionably alludes to testaments, (Hebrews 9:16;) but here I prefer to take it simply for the covenant which God made. The analogy from which the apostle argues, would not apply so strictly to a testament as to a covenant. The apostle appears to reason from human bargains to that solemn covenant into which God entered with Abraham. If human bargains be so firm that they can receive no addition, how much more must this covenant remain inviolable?