What does Exodus 8:24 mean?
A recurring theme in the book of Exodus is that God always fulfills His promises. Whatever He says will happen, does happen. When Moses and Aaron connect a plague of judgment to a specific time, from a specific animal, with a specific intensity, it is meant to prove that they speak on behalf of the One True God. Egyptian idols who supposedly have power over these elements are shown to be worthless. As promised (Exodus 8:20–23), Egypt is engulfed in flies. As with the plague of frogs (Exodus 8:12–15), Pharaoh will attempt to negotiate peace only to break his promises once the immediate danger is gone (Exodus 8:31–32).Two psalms mention this plague specifically. In Psalm 78:45 we are told the flies "devoured [the Egyptians]." Psalm 105:31 states when God spoke "there came swarms of flies." Even generations later, this plague was noted as an important part of God's work to free His people. The nature of this and other catastrophes was so severe that the Lord used them to motivate Israel to obey God's laws (Deuteronomy 7:12–16; 28:58–63). God's judgment was not exclusive to Egypt. When the Jews made a golden calf and worshiped it under the leadership of Aaron, God sent a plague upon them as well (Exodus 32:35).