bible says dark will get darker and light will get lighter

God had purposed to judge Egypt by showing it no mercy.

For the Egyptians, however, it was a mass of darkness. Once the Angel of the Lord, or the cloud, as it was described, moved between the Israelites and their Egyptian foes, the cloud continued to be a source of light for the Israelites. We need not fear the enemy we need only go forward, trusting in the Lord of light to guard us from our enemies.

He is the one who guards us and protects us from the accusations and fiery attacks of Satan. And this is how it is with Christ: He stands as our Advocate. He stands between them and those who seek to undo them. Here we see God not only as the one who leads His people faithfully through the wilderness, but as the one who protects them from their enemies. We read in the passage before us that the Angel of the Lord moved from guiding the Israelites through the wilderness to guarding them from behind against the advances of the Egyptian army. In Genesis, we read that God separated the light from the darkness by the power of His word. The opening pages of Scripture begin with the theme of separation, a theme that is carried throughout the revealed Word of God until the record of God’s final judgment of mankind.

Bible says dark will get darker and light will get lighter