Pharaoh very quickly regretted letting the Israelites go one God had delivered them out of slavery. He chased after them and God gave Moses the power to part the Red Sea, bring the Israelites through the trenches, Egyptian soldiers following close behind, and delivered them to the other side while ultimately destroying the Egyptians that had chased after them.
'And I will harden Pharaoh's heart, and he will pursue them, and I will get glory over Pharaoh and all his host, and the Egyptians shall know that I am the Lord ." And they did so. ' Exodus 14:4
God wanted everyone, Israelites and Egyptians, believers and non-believers, to know that He is Lord Almighty and He is all powerful. He wanted them to know that He is greater than the Egyptians many false gods.
One very interesting thing is that Egyptian history does not document any of these events. The Egyptians were a very proud people and it was actually not uncommon for a Pharaoh to not report on their failures and defeats. It was also pretty common for them to change official records and stories so that the official records were more in their favor.
The Song of Moses and Miriam
' Your right hand, O Lord , glorious in power, your right hand, O Lord , shatters the enemy.' Exodus 15:6
The right hand of God refers to His power and authority, which ultimately becomes the seat of authority occupied by Jesus.
' "Who is like you, O Lord , among the gods? Who is like you, majestic in holiness, awesome in glorious deeds, doing wonders?' Exodus 15:11
It was actually not until after the Exodus that Israelites started to really understand that there is only one God.
Why are songs included in the Bible?
Music has a central role in worship. Throughout scripture, God requests songs be sung for Him. This song during the Exodus was likely a joyful outburst of praise and worship as the Israelites had just been saved and set free.
Who was Miriam?
She was a priestess, sent with her brothers, Aaron and Moses, to lead Israel. God used her and spoke through her, which gave her a sort of authority. She is who led the worship after the Exodus.
Bread from Heaven
Once the Israelites were delivered from slavery, God led them out into the wilderness. While in the wilderness the Israelites began to again test God. Even after all God had done for them they still did not trust in Him. They groaned and complained, and because they continued to test God, God tested them. Moses reminded the Israelites that their grumblings against them (Moses and Aaron) were actually grumblings against God since Moses and Aaron were leading them in God's will.
'And Moses said, "When the Lord gives you in the evening meat to eat and in the morning bread to the full, because the Lord has heard your grumbling that you grumble against him—what are we? Your grumbling is not against us but against the Lord ." ' Exodus 16:8
God told the Israelites that each day they can only gather enough food for that day, and no more. This was a test to see if they would listen. When someone would keep leftovers, in the morning is was rotten. On the sixth day they were told to gather 2 days' worth and save the second portion for the next day, which was the first observance of the Sabbath; a holy day of rest and no work. God wanted them to rest and not have any work on the seventh day.
'See! The Lord has given you the Sabbath; therefore on the sixth day he gives you bread for two days. Remain each of you in his place; let no one go out of his place on the seventh day." ' Exodus 16:29
'Now the house of Israel called its name manna. It was like coriander seed, white, and the taste of it was like wafers made with honey. Moses said, "This is what the Lord has commanded: 'Let an omer of it be kept throughout your generations, so that they may see the bread with which I fed you in the wilderness, when I brought you out of the land of Egypt.'" And Moses said to Aaron, "Take a jar, and put an omer of manna in it, and place it before the Lord to be kept throughout your generations." As the Lord commanded Moses, so Aaron placed it before the testimony to be kept. The people of Israel ate the manna forty years, till they came to a habitable land. They ate the manna till they came to the border of the land of Canaan. ' Exodus 16:31-35
God provided them with manna to eat every day for 40 years while they wandered the wilderness. Then, when they came to the promised land of Canaan He told them to keep a small amount of manna that He would preserve through generations so that future generations could see what God had fed them in the wilderness.
Water from the Rock
God's people continue to put Him to the test, complaining to Moses about what they do not have. So God, again testing them in return tells Moses to go with the elders of Israel to the rock at Horeb and strike it with his staff and He will make water flow from it.
The Amalekites Defeated
The Amalekites were descendants of Esau who made a living raiding other tribes and killing for their pleasure. They came to attack the Israelites, and God had Joshua take some men to fight the Amalekites. While they fought, Moses went up on the mountain with his staff. Whenever Moses had his hands raised with his staff, the Israelites would prevail. When he would rest his hands, Amalek prevailed. When Moses grew too weary to keep his hands up, Hur (Miriam's husband) and Aaron sat him on a rock and held his hands up to steady them until Joshua overwhelmed Amalek.
'And Moses built an altar and called the name of it, The Lord Is My Banner, saying, "A hand upon the throne of the Lord ! The Lord will have war with Amalek from generation to generation." ' Exodus 17:15-16
Jethro, Moses's father-in-law, heard of everything that had happened to Moses and the Israelites, and came to Moses with Moses' wife and children to provide a burnt offering to God. Moses did as his father-in-law had recommended, and Jethro went back home.
'Now obey my voice; I will give you advice, and God be with you! You shall represent the people before God and bring their cases to God, and you shall warn them about the statutes and the laws, and make them know the way in which they must walk and what they must do. Moreover, look for able men from all the people, men who fear God, who are trustworthy and hate a bribe, and place such men over the people as chiefs of thousands, of hundreds, of fifties, and of tens. And let them judge the people at all times. Every great matter they shall bring to you, but any small matter they shall decide themselves. So it will be easier for you, and they will bear the burden with you. If you do this, God will direct you, you will be able to endure, and all this people also will go to their place in peace." ' Exodus 18:19-23