v1-2: The first born, having avoided death by the Passover, were consecrated, set apart, for God. This was a single event, rather than a process. It had either happened or it hadn't.
v3-10: Moses was looking forward, to the people celebrating the Passover when they arrived in Canaan.
v3: The day was to be remembered, because on this day the Lord brought His people out of Egypt, out of the years of bondage and hardship. The simple command, to"eat nothing containing yeast", would remind them as a people of the events of that time.
v4: The month of Abib, the first month, a new start (see 12.2, the first of the months). The Passover was to be remembered at the beginning of the year.
v5: There was no doubt that the people would reach Canaan. The celebration of the Passover would be a testimony to the people in Canaan. In light of Josh 5.10-12, this seems to be a hint that Passover would not be celebrated during the wilderness journey. Of course, at this stage, it was not expected that a 40 year gap would occur.
v6-7: All yeast to be removed from their homes. This was part of the re-enactment of the first Passover.
v8: The details of the Passover were to be passed on to succeeding generations. The feast was therefore celebrated in the family home. In this way, the Passover was seen to be a personal deliverance;"what the Lord did for me". See Gal 2.20; Eph 5.25. The deliverance from Egypt was both national and personal, and our salvation in Christ must also be understood in both ways.
v9: The physical sign, on the hand, on the forehead, on the lips. Something to be remembered.
v10: An annual feast had to be maintained. In later years this was neglected; see 2 Kings 23.21-23.
v11-13: First born sons to be set apart. This aspect of the Passover was to be applied to all the people and to their animals. Notice that the arrival in Canaan was without doubt, for God would fulfil His purpose. The donkey, an unclean animal, had to be redeemed with a lamb. This pictures Christ's redemption for us by the shedding of His blood, 1 Pet 1.18-19. The choice is stark and real - redemption or death. Like the Passover feast itself, this practice was a testimony of God's deliverance of His people from Egypt.
v14: Again, there was an opportunity to explain to the family what the ritual meant.
v15: The first born son was sacrificed to the Lord. This reminds us of Abraham's sacrifice of Isaac (Gen 22).
v16: The sign of the first born son, that the Lord had delivered His people with a powerful hand. See also v9.
v17-18: God led His people, not through the land of the Philistines, but towards the Red Sea. This was a longer route, but the better way. In this respect, we see that salvation is an on-going process as well as a once-only event.
v19: The promise of God through Joseph (Gen 50.24-25) had been fulfilled, and his bones were taken from Egypt.
v21-22: The permanent, visible presence of the Lord. The Christian enjoys that same presence by the Holy Spirit indwelling us.