At first, it seemed like a contrivance, just an excuse to do something. “The God of the Hebrews has met with us. Now let us take a three-day journey into the desert to offer sacrifices to the LORD our God, or he may strike us with plagues or with the sword” (Exodus 5:3). God really wanted Israel to escape, so He (and they) made this trumped up reason to leave Egypt.
But it was not a contrivance. In fact, it was God’s reason from the beginning (remember 4:21-23). It is the repeated reason for Israel to leave Egypt. They cannot worship God in that land.
Why not? Isn’t God everywhere? Where people are allowed the freedom to assemble, can they not worship the Lord?
Actually, often the answer is “no.”
First, God wanted them to worship Him in a special place. Second, he wanted them to worship Him as free people, not as slaves. How sovereign could the Lord be if His own people were enslaved by worshipers of another god?
But perhaps just as important, Israel could not live as the holy people God expected them to be surrounded by the paganism that was Egypt. As the Exodus story unfolds, you will notice the continual influence of a pagan culture on the people of God.
As the plagues unfold, God is convincing the Egyptians it is in their best interest to allow Israel to leave. But God is also convincing Israel that Egypt isn’t an attractive place to live at all. Who would want to live in the land where the water smelled of blood and where frogs (and their carcasses) were everywhere you moved?
We assemble for worship as a community, but worship is also a daily thing, where God is honored by our plans and lives. When we forget that, or are drawn away from it by the allure and comfort that is our culture, God is not worshiped and he calls us to “come out from among them and be separate” (Isaiah 52:11), just as he called Israel.