Synopsis of the Books of the Bible, by John Nelson Darby, [1857-62], at sacred-texts.com
When God had thus revealed Himself, according to His establishment of blessing in power on the earth, through the priestly king Melchisedec, naturally the actual blessing of the chosen people finds its place; and we come down to the actual earthly scene, and in chapter 15 have the detailed instruction of the Lord to Abram, regarding the earthly seed and the land given to him, the whole confirmed by a covenant where God, as light to guide and furnace to try, deigns to bind Himself to the accomplishment of the whole. Death makes it sure. Jehovah confirms thus the covenant in going, in grace, through that which bound Him; Abram, heir of the promises, undergoes the terror and shadow of it. It is not here precisely expiation, but what belonged to the confirmation of the promises, by the only thing which could establish them in favour of man a sinner. It is evident that this unfolding of God's ways, and the establishment of the covenant embraces (though the covenant be made in favour of the earthly people) new and important principles. God Himself was Abram's defence and portion. That is the highest portion of all, so far as anything given to man can go. [See Note #1]
But Abram feels yet his connection with the earth as an abiding place in connection with the flesh, and it was indeed God's purpose so to bless him. That is in its nature Jewish, and we have consequently the Jewish portion unfolded. The whole scene descends thus here to earthly hopes, and promises, and covenant, and the land. Abram's mind goes down; for it is going down when God says (on his having refused everything from the world, in view of the world to come as a future hope), 'I am thy reward,' as He had been his shield to say, What wilt thou give me? But the divine word uses it, to unfold on God's part His purposes in this respect, which, as regards the government of this world, are of real importance. I have no heir, says Abram; nothing to continue, by a family tie, the possession of my inheritance on earth, according to promise; for on earth, where men die, there must be succession. And so it was to be. But still, as to the earth, it was to be by dependence on Jehovah, by promise, and by faith. Although connected here with the earth, it was not according to nature: on this footing all was foreclosed against Abram he had no seed. Hence, the seed of faith and promise comes forth not indeed the one seed but the Jews as children of promise. The principle is set forth and faith counted for righteousness while Abram believed God. Thus, for this world, Israel was the seed of promise, the heir. Then comes covenant as to the land, according to promise made in the call of Abram. The Lord binds Himself to Abram according to death, as we have seen (for indeed it is assured in the death of Christ, without which they could have nothing). This is, as to present fulfilment, connected with the suffering of the people in Egypt, and their subsequent deliverance, when the oppressors of the people and the usurpers of the inheritance would both be judged.
The character of the act by which the covenant was made, we have already noticed. The reader may compare Jer 34:18-19, as to the force of this act. It is not here, moreover, a promise by which Abram is called out by faith, but the assuring the inheritance to his seed by covenant, and here without condition. It is the promise to Israel, the seed of promise, the heir in connection with the earth and flesh. Remark, moreover, that the prolonged sorrow and oppression of God's people the delay of the promised heir is in connection with the patience of God towards those that are to be judged. (Compare Pe2 3:9.) We may remark that the oppressors of Israel are judged for the sake of Israel, the usurpers of his inheritance for him.
Here the laying out of God's plans and purposes closes, even as to the earthly people, and man's ways, and God's ways for their fulfilment, begin to be unfolded with chapter 16 [See Note #2], with the paths of those, or hindrances from those, with whom His people may be connected in any way. These are developed up to chapter 23 when Abraham ceases to be the representative of the stem of promise. Sarah dies, the vessel of the seed of promise, and the risen heir comes into notice as the one whom God sets forth. They that are born after the flesh precede those who are born according to promise. We cannot but remark, what gives so striking a character to the book of Genesis, and such freshness to all that is in it (particularly to what we have gone through hitherto), how all the great principles of man's estate and of God's ways are brought out in it. It is a heading and summary of all man's state and God's ways with him in it not of redemption, though sacrifice and covering of sin be found, nor of its glorious results. Redemption is in Exodus. Man's state and God's ways and fundamental promises are here.
Note #1
The declaration of God in the beginning of chapter 15, is in connection with Abram's refusing to take anything from the world, as related in the end of chapter 14.
Note #2
Chapter 15 stands by itself, between the general principles already treated of and the historical account which follows, but which, though historical, gives great leading principles which, with the exception of Isaac, apply to Israel and the earth. It is the unconditional promise as to Israel, the land, and the covenant. In the subsequent chapters, however, we find the promised seed.