Aaron and Moses went to the Pharaoh and told him, "Hey, god wants you to let all the Israelites go have a festival in the wilderness. So they'll need some time off, I guess."
And the Pharaoh said, "Um, who wants?"
And Moses said, "You know. God."
"Nah, I don't know that guy. I don't think so."
Aaron and Moses persisted, "Come on, we need a three day weekend or god's gonna be mad at us and uh, strike us down! With plagues perhaps!" (I don't remember god saying this, but it probably seemed a plausible thing to our protagonists.)
The Pharaoh was having none of it. "Look, I can't spare anyone. Shit must needs be done."
So Moses and Aaron went away. The Pharaoh, meanwhile, in a dick move worthy of a living god, decided to tell the slaves they now had to gather their own straw for the bricks they had to make. He made certain to tell the slave drivers that they still had to meet their quotas. Or, you know, whipping.
This didn't turn out so well. The bricks didn't get made and the Israelites were roundly flogged, and to boot, called lazy. Which could be the definition of insult to injury.
They were pissed at Moses and Aaron. Understandably.
Understandably, Moses was confused and asked god, "Um, is this going the way you intended? Cause it seems like things are worse than they were. Thought you were gonna help with all this?"
Actually this part of the story is understandable from this far ahead in history: any time political or social change must be effected, things always get worse before they get better, and you have to sort of bear with the process, having faith that the end result will be a better, freer society, even though getting pelted with tear gas and shot with rubber bullets and pummeled with fire hoses fucking sucks. So I can see that this story rang true to the Israelites who made it out of slavery--it got worse when they tried to change things, but they had faith that trying to change things was better than letting them stay the same.
Any time I read a story about humans doing this sort of thing I'm proud to be a human.