"There is gospel in the maternal promise, gospel in the ceremonial law, and gospel in many of the Prophets, as Isa. 53 and 54; 55:1–3, 6, 7; Jer. 31:33, 34; Ezek. 36:25–28. In fact, there is a gospel current running through the whole of the Old Testament, which reaches its highest point in the Messianic prophecies."The substance of the gospel promise/covenant of grace runs through the Old Testament and comes to fruition in the person of Jesus Christ, "Lamb of God who takes away the sins of the world."
Gal. 3:14 so that in Christ Jesus the blessing of Abraham might come to the Gentiles, so that we might receive the promised Spirit through faith.
Gal. 3:29 And if you are Christ's, then you are Abraham's offspring, heirs according to promise.
Gal. 4:4 But when the fullness of time had come, God sent forth his Son, born of woman, born under the law, 5 to redeem those who were under the law, so that we might receive adoption as sons.
Heb. 1:1 Long ago, at many times and in many ways, God spoke to our fathers by the prophets, 2 but in these last days he has spoken to us by his Son, whom he appointed the heir of all things, through whom also he created the world.