Isaac and the Covenant
Isaac, the beloved son of Abraham, went to the altar as a sacrifice (Gen 22) at the apparent cost of obliterating the Abrahamic covenant. As the book of Hebrews explains it: “It was by faith that Abraham offered Isaac as a sacrifice when God was testing him. Abraham, who had received God’s promises, was ready to sacrifice his only son, Isaac, even though God had told him, ‘Isaac is the son through whom your descendants will be counted’” (Heb 11:17–18). And Abraham didn’t go to Moriah in obedient despair, he went in the obedience of faith: “Abraham reasoned that if Isaac died, God was able to bring him back to life again. And in a sense, Abraham did receive his son back from the dead” (v. 19).
Bloodshed signals all divine covenants (Exod 24:8; Heb 9:20), and this act of obedience signaled ongoing ratification of the Abrahamic covenant (Gen 22:1–18); however, it wasn’t to be Isaac’s blood that signalled the covenant, it was to be the blood of a sacrifice that God himself would proved. As Abraham approached the altar, “Isaac turned to Abraham and said, ‘Father?’ ‘Yes, my son?’ Abraham replied. ‘We have the fire and wood,’ the boy said, ‘but where is the sheep for the burnt offering?’” (Gen 22:7). Abraham’s answer spoke more than he knew: “God will provide a sheep for the burnt offering, my son” (Gen 22:8a). Then he continued in obedience with altar stones, firewood, and knife—even a knife raised over the beloved son in whom all covenantal hopes rested (Gen 22:9–10). At that point, God stopped the proceedings and provided the needed substitute.
Covenantal Lamb of God
For Abraham, the needed substitute was a ram caught in a thicket (Gen 22:13); for us, it is the beloved Son, whom John introduced this way: “Look! The Lamb of God!” (John 1:29, 36). Abraham and Isaac could never have announced, “This is my blood, which confirms the covenant” (Matt 26:28; Mark 14:24), and the blood of bulls and goat could not establish the new covenant, but only that of Jesus Christ (Luke 22:20; 1 Cor 11:25). So Abraham renamed Morah “Yahweh-Yireh (which means ‘the Lord will provide’)” (Gen 22:14).