After a plague of locusts devours everything that was left by the hail, a ninth plague of darkness settles upon Egypt. It is a thick, palpable darkness "that can be felt" (vs. 21), and it lingers in the land for three days. Yet it is merely symbolic of the terrifying final darkness of the tenth plague that is coming if Pharaoh will not humble himself and submit to God's will in letting the people go.
Pharaoh has almost reached his breaking point, conceding everything except that the Israelites may take their livestock with them when they leave to go worship their God in the wilderness. Moses, however, insists that their animals must go with them so that they will know what to sacrifice to the Lord when they reach their destination (vs. 26).
When Pharaoh refuses this final provision, he throws down the gauntlet. "Get away from me! Take care that you do not see my face again, for on the day you see my face you shall die." Ironically, his words are spoken after a plague of such thick darkness that people literally could not see one another (vs. 23). Pharaoh would rather have the darkness and the plagues and the crushing defeat at the hands of the Lord than bend his knee and his will to the Almighty. He is choosing the darkness of his sin rather than the light of forgiveness and a fresh start with God.
I guess it shouldn't be too surprising that Pharaoh would choose the darkness rather than the light. Years later, Jesus would speak of this same choice that all too many of us make when it comes to yielding to God or persisting in the darkness of our sin: "And this is the judgment, that the light has come into the world, and people loved darkness rather than light because their deeds were evil. For all who do evil hate the light and do not come into the light, so that their deeds may not be exposed" (John 3:19-20).
Do yourself a favor - don't choose the darkness! Come into the light!