Exodus 16:18-20

18And when they measured it by the omer, the one who gathered much did not have too much, and the one who gathered little did not have too little. Everyone had gathered just as much as they needed. 19Then Moses said to them, “No one is to keep any of it until morning.” 20However, some of them paid no attention to Moses; they kept part of it until morning, but it was full of maggots and began to smell. So Moses was angry with them.