Exodus 5

Aaron and Moses tell Pharaoh that God commanded them to go into the wilderness for three days to honor Him. Pharaoh tells them he does not know this God and will not let the enslaved go to worship.

This incident distracted the Israelites from work. Pharaoh decides that the enslaved must be idle if they are making these sorts of requests. He enacts a new rule that the enslaved must find their own straw to form bricks instead of the slavedrivers organizing the tools. He expects the same yield of production, and believes the Israelites are conspiring together to go worship their God.

Remember, Exodus 1 verse 10...the reason for enslavement was that the Egyptian king felt threatened by the capacity of the Israelites because of their large number.