In the 16th Chapter of Exodus, we read that the children of Israel once again begin their complaints against Moses and Aaron.  Rather than praying to God, they complained about Moses and Aaron.  God graciously answered the complaints, but we see that the Hebrews were not accepting the responsibility of their new found freedom.  Their slavish mentality caused them to desire to turn back to Egypt every time they ran into difficulty. 

God not only supplies them with food (manna) but He also supplies them with a sabbath.