PREACHED BEFORE THE GOSPEL UNTO ABRAHAM

Galatians 3:8 And the scripture, foreseeing that God would justify the heathen through faith, preached before the gospel unto Abraham, saying, In thee shall all nations be blessed.

Genensis 12:3 And I will bless them that bless thee, and curse him that curseth thee: and in thee shall all families of the earth be blessed.

Barnes:

In thee shall all nations be blessed –

All nations should be made happy in him, or through him. The sense is, that the Messiah was to be descended from him, and the religion of the Messiah, producing peace and salvation, was to be extended to all the nations of the earth:

Galatians 3:16 Now to Abraham and his seed were the promises made. He saith not, And to seeds, as of many; but as of one, And to thy seed, which is Christ.

Barnes:

It is certain that Abraham’s faith terminated on the promised Seed, that is, Christ whose day he desired to see, and seeing it afar, was glad, John 8:56. “

(“Hereof it followeth,” says Luther on the place, “that the blessing and faith of Abraham is the same that ours is, that Abraham’s Christ is our Christ, that Christ died as well for the sins of Abraham as for us.”)

Jesus said … John 8:56 Your father Abraham rejoiced to see my day: and he saw it, and was glad.