Exodus 16: 15 - 20 (NIV)
'When the Israelites saw it, they said to each other, “What is it?” For they did not know what it was. Moses said to them, “It is the bread the LORD has given you to eat. This is what the LORD has commanded: ‘Everyone is to gather as much as they need. Take an omer for each person you have in your tent.’ ” The Israelites did as they were told; some gathered much, some little. And 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. Then Moses said to them, “No one is to keep any of it until morning.” However, 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.'