The people of God left Elim and continued their journey through the wilderness to the Promised Land. When they became hungry, they did what they usually did – they complained in unbelief! (Exodus 16)
Complaining is an expression of faith in the negative (unbelief in the positive). Faith in the negative empowers the negative to become a reality. It’s all too easy to want to go back to Egypt [trusting flesh rather than God] when you come out of Egypt and the going gets tough. It’s easier to get God’s people out of Egypt than it is to get Egypt out of God’s people!
“Do all things without complaining and disputing, that you may become blameless and harmless, children of God without fault in the midst of a crooked and perverse generation, among whom you shine as lights in the world.” (Phil. 2:14-15)