and in your offspring shall all the nations of the earth be blessed, because you have obeyed my voice.”
Abraham's obedience was graciously accepted; but this was not all: here we have it recompensed, abundantly recompensed, before he stirred from the place; probably while the ram he had sacrificed was yet burning God sent him this gracious message, renewed and ratified his covenant with him. All covenants were made by sacrifice, so was this by the typical sacrifices of Isaac and the ram.
Commenting on Genesis 22:15-19
So Abraham returned to his young men,.... He had left at a certain place with the ass, while he and Isaac went to the mount to worship; and who stayed there till he came to them, according to his order, Gen 22:5; no mention is made of Isaac, but there is no doubt that he returned with Abraham, since we hear of him afterwards in...
And in thy seed, etc. - We have the authority of St. Paul, Gal 3:8, Gal 3:16, Gal 3:18, to restrain this to our blessed Lord, who was The Seed through whom alone all God's blessings of providence, mercy, grace, and glory, should be conveyed to the nations of the earth.