When the Israelites were on their way to the land of Canaan, they came from Elim to the wilderness of Sin. During the period, they were without food for several days. The people murmured against Moses for they wanted food. It was their wish that they were left alone in Egypt where there was plenty of food rather than to die in the widerness.
The Lord called on Moses and informed him that He (Lord) would rain bread (Manna) from heaven for them. The Lord told Moses that he should instruct the Israelites to gather a day’s portion every day. The reason behind this was to test the people’s faithfulness and loyalty to God. They were also instructed to store for the Sabbath day because manna would not be rained for the day.

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After Moses and Aaron had taken the instruction from the Lord, they assured the Israelites that they would soon know that it was the Lord who brought them out of Egypt and they would soon see His glory, for the Lord had heard their murmuring. God made it clear to Moses and Aaron that the people’s murmuring was not directed at them, but against Him (God). The Israelites were gathered in a place and the glory of God was manifested in the clouds. In the evening, quails covered their camp; in the morning white flakes filled everywhere. Moses directed them to gather the flakes on omer, a piece according to the number of people per family, and none should be left over till the following morning.
The story had it that those who disobeyed and gathered more than necessary were punished. Their bread was filled with worms. Moses did not hide his annoyance for their disobedience.

SeeHow Moses prepared the Israelites for the covenant with God and why this preparation was necessary
The nature of God in this episode was revealed as follows:
(i) The episode shows that even when we do not ask God for what we need, He always provides for our needs.
(ii) It equally indicates that God’s endurance is unlimited. This was demonstrated by God when He endured the murmuring and ingratitude of the people of Israel.
(iii) It signifies that offenders would not go unpunished for their disobedience.

Read: the incredible role of Joshua in the story of the twelve spies, and the reasons why God chose him to succeed Moses