Exo 13:1 And the LORD spoke unto Moses, saying,
Exo 13:2 Sanctify unto me all the firstborn, whatsoever openeth the womb among the children of Israel, both of man and of beast: it is mine.

God spared the firstborn of Israel and in return they were to dedicated them to the Lord. I believe this was a type of thanksgiving to God for sparing them their lives. They were to cleanse and dedicate their firstborn to the Lord. They were also to remember the day in which God brought them out of the land of bondage into a new and living way.

This is similar to when Jesus saves us from sin, we are brought out of the bondage of sin into a new and living way.

The blood of Jesus cleanses us from all sin. In the days of Moses they had to undergo cleansing with water, ceremony and service done by the priests. This was temporary until the perfect one that was to come arrived. When Jesus died on the cross for sins and then arose, He made a perfect way in which we are cleansed inwardly. We are changed and made new. This is an inner change done by the Holy Spirit. Until Jesus they had to do rituals, washings, and other things by the priests. Now this is not necessary and if we try to bring this back into our worship we are bringing back what Jesus died to fulfill. We do not need a continual sacrifice since Jesus was the complete final sacrifice for sins.

Man brought sin into the world and only man could free us from sin. A man had to be sacrificed. No man from Adam until Christ was worthy to be a perfect sacrifice because all have sinned. Jesus was God who came into the flesh and was born of a woman. He lived all His earthly life without sin. He alone was worthy to make Himself a sacrifice for sins and die in our place. If we reject Jesus, we will die in our sins without being redeemed. We will enter eternity in hell because we did not accept God's plan for us to escape hell and enter eternal life.
Animal sacrifices had to be made continually until the perfect final sacrifice was ready to come into the world. The animal sacrifices could not change the inner man. By faith they were offered until Christ came. Now we do not need ceremonial cleansing because we are sanctified by the blood of Jesus Christ.

Exo 13:3 And Moses said unto the people, Remember this day, in which ye came out from Egypt, out of the house of bondage; for by strength of hand the LORD brought you out from this place: there shall no leavened bread be eaten.

Leaven represents sin and bondage. They were to not have any in the house during this time of remembrance.

Exo 13:4 This day came ye out in the month Abib.
Exo 13:5 And it shall be when the LORD shall bring thee into the land of the Canaanites, and the Hittites, and the Amorites, and the Hivites, and the Jebusites, which he swore unto thy fathers to give thee, a land flowing with milk and honey, that thou shalt keep this service in this month.
Exo 13:6 Seven days thou shalt eat unleavened bread, and in the seventh day shall be a feast to the LORD.
Exo 13:7 Unleavened bread shall be eaten seven days; and there shall no leavened bread be seen with thee, neither shall there be leaven seen with thee in all thy quarters.
Exo 13:8 And thou shalt show thy son in that day, saying, This is done because of that which the LORD did unto me when I came forth out of Egypt.
Exo 13:9 And it shall be for a sign unto thee upon thine hand, and for a memorial between thine eyes, that the LORD's law may be in thy mouth: for with a strong hand hath the LORD brought thee out of Egypt.
Exo 13:10 Thou shalt therefore keep this ordinance in his season from year to year.
Exo 13:11 And it shall be when the LORD shall bring thee into the land of the Canaanites, as he swore unto thee and to thy fathers, and shall give it thee,
Exo 13:12 That thou shalt set apart unto the LORD all that openeth the matrix, and every firstling that cometh of a beast which thou hast; the males shall be the LORD's.
Exo 13:13 And every firstling of an ass thou shalt redeem with a lamb; and if thou wilt not redeem it, then thou shalt break his neck: and all the firstborn of man among thy children shalt thou redeem.

The firstborn of clean animals were the only ones to be sacrificed. The first born of other animals and humans were to be redeemed.

They had to pay a ransom or a price to be redeemed.
Jesus paid the price for all who would receive it, to be redeemed from sin and reconciled to God.

Exo 13:14 And it shall be when thy son asketh thee in time to come, saying, What is this? that thou shalt say unto him, By strength of hand the LORD brought us out from Egypt, from the house of bondage:
Exo 13:15 And it came to pass, when Pharaoh would hardly let us go, that the LORD slew all the firstborn in the land of Egypt, both the firstborn of man, and the firstborn of beast: therefore I sacrifice to the LORD all that openeth the matrix, being males; but all the firstborn of my children I redeem.
Exo 13:16 And it shall be for a token upon thine hand, and for frontlets between thine eyes: for by strength of hand the LORD brought us forth out of Egypt.

These stories can be great teaching tools for children. They were to pass them on from generation to generation.

Exo 13:17 And it came to pass, when Pharaoh had let the people go, that God led them not through the way of the land of the Philistines, although that was near; for God said, Lest peradventure the people repent when they see war, and they return to Egypt:

They were still weak and just starting out. God knew they were not yet ready to face war.

Exo 13:18 But God led the people about, through the way of the wilderness of the Red sea: and the children of Israel went up harnessed out of the land of Egypt.
Exo 13:19 And Moses took the bones of Joseph with him: for he had straitly sworn the children of Israel, saying, God will surely visit you; and ye shall carry up my bones away hence with you.

It must have been written down someplace where they would see and do as Joseph wished. It could be that the other brothers of Joseph were buried in their own land similar to Jacob but Joseph had remained in Egypt until the time of their departure back to the land of Canaan.

Exo 13:20 And they took their journey from Succoth, and encamped in Etham, in the edge of the wilderness.
Exo 13:21 And the LORD went before them by day in a pillar of a cloud, to lead them the way; and by night in a pillar of fire, to give them light; to go by day and night:
Exo 13:22 He took not away the pillar of the cloud by day, nor the pillar of fire by night, from before the people.

Imagine being led of the Lord in this way. I believe that Jesus was with them in the cloud to lead them.

Since God Himself did not usually appear to men, any appearances of God was probably the Son of God, Jesus. That is my speculation though although there were verses in the new to support this.

1Co 10:4 And did all drink the same spiritual drink: for they drank of that spiritual Rock that followed them: and that Rock was Christ.

Christ was the rock that followed them all through the wilderness. Christ was the rock, not Peter upon which the church was built. The foundation is Christ and the congregation of the Lord is built upon Christ, the rock of our salvation.

Exodus 14