What does Exodus 8:10 mean?
Pharaoh's magicians had appeared to duplicate the Lord's miraculous signs (Exodus 7:10–12, 22–23). But whatever success they had in replicating the plague of frogs (Exodus 8:6–7) was limited. Instead of ignoring the command to release the nation of Israel (Exodus 8:1–2), Pharaoh summons Moses and Aaron to make a deal: if the frogs are taken away, he will release the Hebrews (Exodus 8:8).This means the Egyptian occultists could summon frogs, but not drive them away. Despite worshipping Heqet, a frog goddess, the Egyptians are forced to ask a slave nation to appeal to their own God for relief. Moses replied with an offer for Pharaoh to choose when the plague would be lifted (Exodus 8:9). This would remove any doubts that what happened was a coincidence. Both the start and end of the disaster would be credited to the God of Israel, alone.
It seems strange, at first, that Pharaoh's answer is not, "remove the frogs immediately." It's possible Moses only gave Pharaoh a few options. Also, ancient Egyptian religion made heavy use of incantation and ritual. In Pharaoh's mind, "tomorrow" might have been the soonest such a thing could be done. But as expected (Exodus 3:19–20), lifting this plague only makes Pharaoh more stubborn, and he will go back on his bargain almost immediately (Exodus 8:15).
Ancient literature often uses a mirror-image structure. This is a "chiasm," where ideas are arranged towards a crucial point, then repeated in reverse order. Pharaoh mentions pleas to the Lord (Exodus 8:8), ending the plague is discussed (Exodus 8:9–10). Then comes the central idea: that the Lord is glorified. Next, the end of the plague is mentioned (Exodus 8:11) and Moses pleads with the Lord (Exodus 8:12).