Then the LORD said to Moses, “Go back to Pharaoh and announce to him, ‘This is what the LORD says: Let my people go, so they can worship me. If you refuse to let them go, I will send a plague of frogs across your entire land. The Nile River will swarm with frogs. They will come up out of the river and into your palace, even into your bedroom and onto your bed! They will enter the houses of your officials and your people. They will even jump into your ovens and your kneading bowls. Frogs will jump on you, your people, and all your officials.’ ”
Then the LORD said to Moses, “Tell Aaron, ‘Raise the staff in your hand over all the rivers, canals, and ponds of Egypt, and bring up frogs over all the land.’ ” So Aaron raised his hand over the waters of Egypt, and frogs came up and covered the whole land! But the magicians were able to do the same thing with their magic. They, too, caused frogs to come up on the land of Egypt.
Then Pharaoh summoned Moses and Aaron and begged, “Plead with the LORD to take the frogs away from me and my people. I will let your people go, so they can offer sacrifices to the LORD.” (Exodus 8:1-8)
Tyrants are not quick to keep their promises. As his nation was overrun with frogs, the Pharaoh recognized that they came from the God of the slaves, and he asked Moses to get his god to send them away. In exchange, Pharaoh promised to do just what the slave God said.
But of course, this was but the second plague that had come upon the land of Egypt, and like those before, though it was annoying, it wasn’t exactly devastating to his kingdom. Frogs don’t bite, they just make noise and startled people by their presence. And they were messy and really, you didn’t want them in bed with you, or in your food.
But like many a tyrant after him, who would ask for concessions, and then when they were given, would ask for some more and who never, ever did what was promised, so the Pharaoh was quick to give in to Moses. But once he got what he wanted, he felt no obligation to follow through on his promise. After all, he was talking to slaves and promises to slaves were meaningless. What could a slave do, after all if you broke a promise? Who cared what a slave thought? They were already resentful; another injustice piled on a lifetime’s worth of them, wouldn’t change their performance. Slaves were property; why worry about what you said to them? As well worry about what you said to your horse or donkey or chamber pot. Pharaoh underestimated the sort of God the slaves had–one who cared about the oppressed and one who was willing—and able—to help them. God will not forget about us.