Pharaoh requires the slaves to meet their daily quota of brick-making although he is no longer supplying some of the raw materials they need to make the bricks. He deliberately sets them up to fail, so he can pretend that their failure is their own fault. When they fail, their overseers get beaten.
In response to the overseers’ reasonable protest, Pharaoh mocks the Israelites’ request (not made by the overseers themselves) to go sacrifice to the Lord (5:17). Clearly the authority of the Lord and the authority of Pharaoh are on collision course; Pharaoh’s service is now conflicting with serving the Lord. Indeed, as a jealous God the Lord allows them to serve no other gods (20:5)—including Pharaoh, who thought he was one. Although Pharaoh did not likely demand that Israelites serve Egyptian gods, his demand for their service was now conflicting with the demand of YHWH.
And between the Lord and Pharaoh, these Israelite overseers are currently caught in the middle. Moses had promised liberation; instead, in the short run, they are beaten. When the abused overseers left Pharaoh they confronted Moses and Aaron who were waiting to meet them (5:20)—and laid into them (5:21). Moses and Aaron seemed like false prophets with false promises, who had simply made matters worse with Pharaoh, who reigned over them. They blamed not God but Moses and Aaron: “May the Lord judge you” (5:21; cf. Gen 16:5; Judg 11:27; 1 Sam 24:12). “You made us stink to Pharaoh and his servants,” they protested. The term for “stink” usually refers to the aroma of a sacrifice pleasant to God, but here it is a bad smell. Moses’s words had given Pharaoh an excuse to harm them worse, though they were probably too useful to Pharaoh for him to literally “kill” them as they insisted.
Sometimes we give up too quickly on God’s promises or God’s call, the vision he has given us to serve him. Conflict usually precedes victory, and suffering precedes triumph. Rarely do God’s victories come to us cheaply, and what does come cheaply is usually quickly forgotten (cf. Deut 6:10-12; 32:15). Suffering does not mean that God is not faithful; in fact, his path usually leads through hardship at the beginning. God has promised us the world to come, but in the present we still share in that promised world’s birth pangs.