Ezekiel 32: 7-8
When I blot you out, I will cover the heavens
and make their stars dark;
I will cover the sun with a cloud,
and the moon shall not give its light.All the bright lights of heaven
will I make dark over you,
and put darkness on your land,
declares the Lord God.
Matthew 27: 45-54
Now from the sixth hour there was darkness over all the land until the ninth hour.
And about the ninth hour Jesus cried out with a loud voice, saying, “Eli, Eli, lema sabachthani?” that is, “My God, my God, why have you forsaken me?” And some of the bystanders, hearing it, said, “This man is calling Elijah.” And one of them at once ran and took a sponge, filled it with sour wine, and put it on a reed and gave it to him to drink. But the others said, “Wait, let us see whether Elijah will come to save him.” And Jesus cried out again with a loud voice and yielded up his spirit.
And behold, the curtain of the temple was torn in two, from top to bottom. And the earth shook, and the rocks were split. The tombs also were opened. And many bodies of the saints who had fallen asleep were raised, and coming out of the tombs after his resurrection they went into the holy city and appeared to many. When the centurion and those who were with him, keeping watch over Jesus, saw the earthquake and what took place, they were filled with awe and said, “Truly this was the Son of God!”
Colossians 2: 13-15
And you, who were dead in your trespasses and the uncircumcision of your flesh, God made alive together with him, having forgiven us all our trespasses, by canceling the record of debt that stood against us with its legal demands. This he set aside, nailing it to the cross. He disarmed the rulers and authorities and put them to open shame, by triumphing over them in him.
The "Day of the Lord" is a term used in the prophetic texts of the Old Testament to describe a coming day of God's judgment. In the Old Testament reading from Ezekiel, it refers specifically to God's verdict on Pharoah, where God condemns Pharoah for his pridefulness and his idolatry with other gods; in a future tense, 'the day of the Lord' points to Christ's second coming, his 'parousia', where he will return to 'judge the living and the dead' and to separate his sheep from the goats.
Often "the day of the Lord" in the Bible points to apocalyptic scenes of destruction and death, but if we look at our reading from Matthew, it also points to eternal life: God the Father pouring out judgment on His Son, standing in our place, for the sake of the entire world. On the cross, Jesus Christ was forsaken for us, as the entire weight of our sin was placed on him and he bore the guilty verdict we deserved so that we could go free. Jesus is our propitiation, as he turned away God's wrath from us, and placed it squarely on him, like the scapegoat described by Moses, used on the Day of Atonement, on which Israel's sins were placed before it was driven into the wilderness.
However, there was another judgment that was delivered on the cross. Not only Christ was forsaken, but the powers of death, sin and Satan were 'disarmed', as St. Paul writes in his epistle, in the act of Christ's substitutionary sacrifice that fulfilled what Genesis 3:15 had promised. As Christ paid the debt for sin, he cancelled the law's death sentence standing over us, and Satan's dominion over us, reverting the fall committed by Adam so we can approach God as his blameless children, whose sins God has promised to remember no more. The cross is therefore the second Tree of Life that has reconciled man and God, whereas the first Tree broke that relationship, as St. Paul writes in Romans 5,
Therefore, just as sin came into the world through one man, and death through sin, and so death spread to all men because all sinned— for sin indeed was in the world before the law was given, but sin is not counted where there is no law. Yet death reigned from Adam to Moses, even over those whose sinning was not like the transgression of Adam, who was a type of the one who was to come.
But the free gift is not like the trespass. For if many died through one man's trespass, much more have the grace of God and the free gift by the grace of that one man Jesus Christ abounded for many. And the free gift is not like the result of that one man's sin. For the judgment following one trespass brought condemnation, but the free gift following many trespasses brought justification. For if, because of one man's trespass, death reigned through that one man, much more will those who receive the abundance of grace and the free gift of righteousness reign in life through the one man Jesus Christ.
Therefore, as one trespass led to condemnation for all men, so one act of righteousness leads to justification and life for all men. For as by the one man's disobedience the many were made sinners, so by the one man's obedience the many will be made righteous. Now the law came in to increase the trespass, but where sin increased, grace abounded all the more, so that, as sin reigned in death, grace also might reign through righteousness leading to eternal life through Jesus Christ our Lord.