15 Brethren, I speak in terms of human relations: even though it is only a man’s covenant, yet when it has been ratified, no one sets it aside or adds conditions to it. 16 Now the promises were spoken to Abraham and to his seed. He does not say, “And to seeds,” as referring to many, but rather to one, “And to your seed,” that is, Christ.
Paul had just finished writing that the blessing of Abraham would come to all, including Gentiles, who receive the promised Spirit by faith (vs. 14). That blessing refers to having a right standing before God—in other words, justification; and that justification comes to us apart from the Law of Moses.
Paul now continues to build his epic defense of the gospel of grace. God had made a binding agreement with Abraham that the whole world would be blessed through him (Gen 12:1-3, 22:18). That agreement still stands. Using a human analogy, he points out that a legal contract is binding once it is signed (ratified); it cannot be changed. In the same way, an agreement between God and Abraham is no less binding.
Paul used the word “promises” to refer to the covenant with Abraham, for it was in reality a unilateral agreement. There were three aspects to the covenant: the promise of a land, descendants (i.e. seed) and a blessing. Blessing to the world would come through God’s blessing of Abraham’s descendants in the land God would and did give them. The Lord made this commitment prior to Abraham’s believing, not as a result of his belief (Gen 12). What Abraham’s faith produced was not the promise of blessing, but his own personal righteousness. That was how he himself entered into the blessing, “Then he believed in the Lord; and He reckoned it to him as righteousness” (Gen 15:6). The blessing comes to all who believe with the same kind of faith as Abraham.
The promise, therefore, was not to Abraham only, but to his “seed.” In the original Hebrew word sera translated seed is used in reference to Abraham’s descendants, in the sense that Abraham impregnated his wife, who bore the fruit of children—and all their descendants are called “seed.” The word when used in the sense of descendants never occurs in the plural, but always in the singular (like in English, the singular seed can be used in a collective sense). So the word can refer to a single seed (or descendant) or to multiple seeds (or descendants). Although we ourselves would never have caught this in the OT reading, Paul, under the inspiration of the Holy Spirit, points out this profoundly significant nuance to emphasize that God had one particular seed in mind, namely Christ.
Lord, thank You that though humans may break their contracts and covenants, You do not. Your Son proved to be the ultimate “Promise Keeper.”
I found it very striking when it was first pointed out to me that Abraham did not pass between the pieces of the animals, but he observed two emblems of deity pass between them. Abraham, and we, are beneficiaries of the covenant, but not parties to it. God the father and Christ the Son made the agreement, and fulfilled it!
Amen. A smoking oven and a flaming torch. That was patterned after a certain ancient covenant symbolism where two people who make an agreement cut up an animal and the two walk through it as a way of symbolically saying “Let it be done to me as it was done to these animals if I break my side of the covenant.” Tom, as you pointed out, Abraham did not pass through between the animals. The oven and torch passed between the animal pieces, most likely representing God–it was a unilateral covenant, where God bound himself to it. See Jeremiah 34:18.