The fact that we do not and cannot fill ourselves could not be made more plain. Only a sodden fool can overlook the thundering nature of grace. In the original we have a strong link between vv. The words bondage and serve in Hebrew are forms of the same word. God delivered them from service so that they might enter into service .
Worship is inescapable.
Service is inescapable. We will either serve the god Pharaoh, or the God who throws down Pharaohs. The people demanded water, and God in His grace gave them water from Himself. The people brought a lawsuit against God, but they were on trial, not God. And there He tells Moses to strike the rock, to strike Him, and water comes from Christ to quench the thirst of a disobedient people.