Exodus 16

3 God had given them water, but now they were in need of food. What they had taken from Egypt was running out, and the wilderness was no place to find food. They should have been able to surmise that God could provide for them, but instead of praying to Him they complain against Moses. One wonders if the people considered Moses a "powerful" man or if he was a god in the same way Pharaoh had thought he was a god. Whatever the case, the people looked to Moses to meet their needs, and not to God.

The accusation that Moses brought the Israelites out of Egypt for the purpose of killing them was ridiculous. First, God had already rescued the Israelites from certain death more than once. Secondly, Moses would not gain anything by killing the people.

4 God is willing to provide for the people, but this bread from heaven would be a daily test of their faith and obedience. They were only to gather enough bread each day to meet their needs (i.e., "daily bread").
5 On Friday they were to gather enough for two days so that they would not need to "work" on the Sabbath day -- the day of rest.
6 Moses and Aaron point to God and remind the Israelites that He is the one who rescues them.
7 Moses and Aaron admit that they did not and can not continue to save the Israelites. God alone can provide for them. The Israelites were complaining to God's appointed leaders, but the complaint was really representative of their lack of trust in God.
10 The pillar of cloud and fire remained outside of the Israelite camp. Even though they were His chosen people, they were still sinful and faithless people. If God allowed this manifestation of His presence to be among the people, they would have perished.

The pillar probably became very bright as God gave a further manifestation of His glory.

14 I seem to remember a documentary that attempted to explain "manna." The substance was white and flaky and appeared on plants in the desert. There are limited quantities of the substance found today. However, this does not match the description of the bread given here. It covered the ground, appeared like a grain, and there was enough to feed all of the Israelites.
15 The word "manna" literally means "what is it?"
18 The one who was greedy did not gain anything by working hard. The less rigorous workers were graciously unpenalized. God is interested in our effort, not necessarily our productivity.
20 The people had gathered as much as they needed for one day. Yet, many (or all) of the people rationed themselves. They did not eat what they needed for a day so that they might have something tomorrow if the manna did not show up again. The people blatantly showed their distrust and lack of obedience to God. The people were rewarded with stinky, wormy leftovers.
24 After seeing what happened to the manna during the "work week," it would be a test of their faith to leave the manna overnight. God promised that the manna would not spoil overnight, and it did not.
27 Some people apparently ate their two-day ration on Friday instead of saving half of it for food on Saturday (the Sabbath). They went out expecting to find food, but did not find any. It is obvious that they still did not understand that the manna was provided by the miraculous power of God. If manna were just a natural occurrence it would have appeared all the time (or at times related to other natural occurrences such as seasons, weather, etc.). God leaves no room for "naturalistic" explanations for the food by providing normal manna on five days, double potions on Fridays, and then none on Saturdays. It would forever be a witness that God had indeed miraculously provided for the Israelites.
28 It is true that Christians today make many mistakes and do not always trust God. During those times we should expect to be admonished by God's faithful leaders. The point of such lectures is not to tear us down, but it is to refocus us and encourage us to be more willing to become the kind of people God wants us to be.
32 Remember that this is the same manna that would go bad overnight. God is the creator of this substance, and he can keep it fresh as long as He likes. It appears that the manna survived the wandering in the wilderness, but by the time of Solomon, the manna was no longer in the ark (1 Ki 8:9).
35 As we continue to read these books of Moses we will find that the Israelites were unfaithful many times. Nonetheless, God continued to provide for their needs.