The gravity of the Abrahamic covenant is demonstrated by the “terrifying darkness [that] came down over him” (Genesis 15:12; New Living Translation). This is echoed in the three hours of darkness—from noon until 3 PM—on Abib 14 as Jesus was being crucified (Matthew 27:45), after which the firstborn Son of God died. Similarly, three days of extreme darkness (the ninth plague; Exodus 10:21-23) preceded the death of the Egyptian firstborn and Israel's exodus from Egypt.
The prophet Amos helps tie these three events together:
“And it shall come to pass in that day,” says the Lord God, “That I will make the sun go down at noon, and I will darken the earth in broad daylight; I will turn your feasts into mourning, and all your songs into lamentation; I will bring sackcloth on every waist, and baldness on every head; I will make it like mourning for an only son, and its end like a bitter day. (Amos 8:9-10)
This is a prophecy of judgment on the northern ten tribes of Israel, just as the darkness and death of the firstborn were a judgment on Egypt (Genesis 15:14).
Jesus' crucifixion was a judgment as well—on the nation that rejected its own Creator and King. After His death, “all the crowds that had assembled for this spectacle, when they saw what had taken place, returned home beating their breasts” (Luke 23:48, New English Translation). Their feast had been turned into mourning, “like mourning for an only [S]on,” on the day that the sun went down at noon and the earth was darkened in broad daylight—on the afternoon of Abib 14.
It is not known what Abraham inferred from the terrifying darkness. Darkness sometimes describes the covering God uses when approaching mankind, so He does not annihilate weak flesh by the supreme brilliance of His presence (Exodus 20:21; Deuteronomy 4:11; 5:22-23; II Samuel 22:10, 12; Psalm 18:9, 11; 97:2). Undoubtedly, part of Abraham's terror was the nearness of the awesome God, just as He was on the scene in His deliverance of Israel, as well as in the final hours before the death of His firstborn Son.
Another cause of Abraham's terror may have sprung from an arresting foreshadowing of his own promised son's death, or perhaps he received a horrifying vision of the death of God's Son as covenant-victim and propitiation to open the way for justification by faith.
David C. Grabbe
Why Was Jesus Not Crucified as Passover Began? (Part Two)