John Calvin Commentary Genesis 15:18

"In that day Jehovah made a covenant with Abram, saying, Unto thy seed have I given this land, from the river of Egypt unto the great river, the river Euphrates:" — Genesis 15:18 (ASV)

In the same day the Lord made a covenant. I willingly admit what I have alluded to above, that the covenant was ratified by a solemn rite, when the animals were divided into parts. For there seems to be a repetition, in which he teaches what was the intent of the sacrifice which he has mentioned. Here, also, we may observe, what I have said, that the word is always to be joined with the symbols, so that our eyes are not fed with empty and fruitless ceremonies. God has commanded animals to be offered to him; but he has shown their end and use, by a covenant appended to them. If, then, the Lord feeds us by sacraments, we infer, that they are the evidences of his grace, and the tokens of those spiritual blessings which flow from it.

He then enumerates the nations, whose land God was about to give to the sons of Abram, in order that he may confirm what he said before concerning a numerous offspring. For that was not to be a small band of men, but an immense multitude, for which the Lord assigns a habitation of such vast extent. God had spoken before only of the Amorites, among whom Abram then dwelt; but now, for the sake of amplifying his grace, he recounts all the others by name.

CHAPTER 16.