God institutes the Passover festival.  God's instructions to the Israelites concerning the Passover are very specifically detailed. The great significance of the Passover is in the prophetic symbolism. Some 1500 years later Jesus became the fulfillment of the Passover by becoming the Passover lamb. The days, hours, minutes, the directions and orders concerning the regulations of the Passover are exact. They are specific so that we can recognize the connections between the first Passover and the fulfillment in the crucifixion and resurrection  of Jesus. The prophecies were fulfilled exactly. From the penning up of the lamb on the tenth of the month to the slaughter of the lamb at twilight on the 14th of the month, Jesus fulfilled these prophecies precisely. As we go through this study we will discover many prophecies that point to Jesus and the cross. Details are on the website  www.philandpatti.com concerning the prophetic messianic symbolism of the Passover. Look under A Biblical View of Holy Week. This writing includes a day by day account of the week and an hour by hour account of the crucifixion and resurrection.

As we reviewed the specific instructions concerning the food they were to eat at Passover, it doesn't sound like a very tasty meal.

Psalm 78 is a good review of the exodus, including an explanation of the striking of the firstborn.
Psalm 78:49
He sent on them the heat of His anger, wrath and fury and trouble, by sending evil angels. 

It is very clear from this passage in Psalm 78 that God sent evil angels (demons) to strike the firstborn. Even with God's warning to kill the Passover lamb and place the blood over the doorposts, most likely there were a few of the Israelites who didn't obey.

When God gave the instructions concerning Passover, He told them the following.
Exodus 12:24
Obey these instructions as a lasting ordinance (or law) for you and your descendants.

For the Israelites, for devout Jews today, Passover is a law for them.  They must adhere to every detail of everything. 

However, the following is for Believers in Jesus today.  

Exodus 12:25  

When you enter the land that the Lord will give you as he promised, observe this ceremony. 

We are to observe the Passover.  The Hebrew word "observe" means "to guard, protect, heed, treasure, to hedge about as with thorns".  As we honor and observe Passover, not necessarily adhering to every detail of everything under the law, we are to treasure and protect our remembrance of it. 

Finally, after the final plague of the death of the firstborn, Pharaoh relents and lets the people go.  At this point, it appears that Pharaoh still believes they are taking only a three day journey into the desert to celebrate a festival to the Lord.

However, the Egyptian people had no notion of any three day journey, they urged the Israelites to leave.  God put a desire in the hearts of the Egyptians to give the Israelites articles of silver and gold, and cloth.  These articles originally belonged to the Israelites, as the result of a legitimate sale for food many, many years earlier when Joseph ruled in Egypt. (see Genesis 47).  These articles of gold and silver and costly material will be used in the construction of the tabernacle in the wilderness.  Just an example of the providence of God!

The Israelite men (by most records men were those over age 20 and under age 60, those who were of fighting age) who left Egypt in the exodus numbered 600,000, not counting women and children. Whew!

We must take into account that not all the Israelites left Egypt.  Some remained and others had already left previously and gone into Greece and North Africa.  Three historical reference books that explain these departures: The Common Heritage of the Greeks and Hebrews, Common Background of Greek and Hebrew Civilizations, and Maps of the Ancient Sea Kings. Also there were other people who left with them who were not Israelites.  They will later be known as "the rabble". 

When the Lord instituted the Feast of Unleavened Bread, He said to do this as a remembrance of how He had brought them out of their bondage in Egypt. After Jesus' fulfillment of this feast day, we as Believers are to still remember, but instead of remembering that God brought the Israelites out of Egypt, we remember that Jesus redeems us from a life of bondage in sin.  “This observance will be for you like a sign on your hand and a reminder on your forehead that the law of the Lord is to be on your lips”

A sign on our hand is what we do. A reminder on our forehead is what we think and remember. The law of the Lord should be in what we communicate to others by the way we live our lives.

How do we as Believers observe and honor our remembrance of what God has done for us?  Do we treasure and protect and honor His Holy Days?