(17) Brethren, I speak (i) after the manner of men; Though [it be] but a man's covenant, yet [if it be] (k) confirmed, no man disannulleth, or addeth thereto.
(17) He puts forth two general rules before the next argument, which is the seventh in order. The first is, that it is not lawful to break covenants and contracts which are justly made, and are according to law among men, neither may anything be added to them. The other is, that God did so make a covenant with Abraham, that he would gather together his children who consist both of Jews and Gentiles into one body (as appears by that which has been said before). For he did not say, that he would be the God of Abraham and of his "seeds" (which thing nonetheless should have been said, if he had many and various seeds, such as the Gentiles on the one hand, and the Jews on the other) but that he would be the God of Abraham, and of his "seed", as of one.
(i) I will use an example which is common among you, that you may be ashamed that you do not give as much to God's covenant as you do to man's.
(k) Authenticated, as we say.