Exegetical Notes: Exodus 12:1-13

1 The Lord said to Moses and Aaron in the land of Egypt,

The importance of passover is highlighted in at least two details in the first couple of verses:
1) The specific identification of Moses and Aaron, the first two Levitical priests serve as an example for all others to follow.
2) The detailed instructions of the act of passover prior to the formal giving of the law on Mt. Sinai.

2 “This month shall be for you the beginning of months. It shall be the first month of the year for you.

“the first month” -Verse 2 seems somewhat odd. What’s the significance of noting the beginning of the year? Some suggestions:
1) Perhaps God is emphasizing that all of our lives should revolve around worship of Him.
2)Perhaps God is demonstrating the importance of passover to Israel.
3)Perhaps God is setting up a difference between the Hebrew and Canaanite calendar. The Canaanite calendar was largely based upon agriculture. God wanted the Hebrew calendar based on redemption.

Here we read that God has decided that history determines the calendar, and in particular, the history of God’s saving act of the exodus does so. Whatever might theoretically have been their previous thinking about a calendar, God decreed to his Old Covenant people that they would henceforth have a calendar designed to remind them of how they first became a people—it happened by reason of their deliverance by his mighty hand out of the bondage of the oppressor, an act so important that it was also to be memorialized by a special annual feast, the Passover.
Douglas K. Stuart, Exodus, vol. 2, The New American Commentary (Nashville: Broadman & Holman Publishers, 2006), 273.

3 Tell all the congregation of Israel that on the tenth day of this month every man shall take a lamb according to their fathers’ houses, a lamb for a household.

At its heart, the Passover is a meal, a commemorative feast. Some modern American holidays are feasts (e.g., Thanksgiving and Christmas); others are not (e.g., Labor Day, July 4). Feast holidays have the special emphasis of careful preparation (thus the instruction in v. 3 that the sacrificial animal is chosen four days before the feast so that there be no last-minute arrangements and the possibility of haphazard celebration or lack of availability results) for gathering people together to share a common gratitude and/or remembrance as they share the common meal linked to that gratitude/remembrance. The gathering of an entire family of Israelites (or group of families eating one animal though in separate houses) together at a dinner table helped symbolize the general pattern throughout the nation, that is, the whole nation eating together, though of course at individual locations. In accordance with the feast nature of the Passover, Moses was told that the whole nation (“tell the whole community of Israel”) must be instructed to eat the meal as households, not as individuals. Thus great emphasis is placed on sharing the meat of a single animal. The goal is to have one goat kid or lamb for each full family, “one for each household.” Therefore, if a household were composed of perhaps just one, two or three people, and they could not by themselves consume a whole goat kid or lamb at one sitting, v. 4 provides for sharing the meal with the next-door family, so that everyone at the two houses eats together from a single sacrificed animal and finishes the meat of that animal during the meal. That is the meaning of “share one with their nearest neighbor, having taken into account the number of people there are.” This might produce some situations in which a rather large number of people, consuming a goat kid or lamb, might each get only a relatively small portion of meat to eat. But the alternative—meat left over, or someone being forced to gorge himself in order to finish off all the meat in one sitting—was strictly to be avoided. Thus the statement at the end of v. 4, “You are to determine the amount of lamb needed in accordance with what each person will eat,” or as it might be more clearly translated, “You must calculate the amount of goat kid or lamb (meat) each person will eat relative to the number of people.” The principle was thus: Everyone had to eat the meat, and all the meat had to be eaten.
Douglas K. Stuart, Exodus, vol. 2, The New American Commentary (Nashville: Broadman & Holman Publishers, 2006), 273–274.

Important points of application from the above quote:
1) “a feast” – we should celebrate the redemption God provides from our sin.
2) “careful preparation”/”animal chosen four days before” – Worship doesn’t occur haphazardly (not that in cannot be spontaneous). It should be meaningful.
3) on celebrating by household and family – corporate celebration of God’s redemption is meaningful and important. We live in community, God is redeeming a people. Although salvation occurs in each individual heart, God’s Kingdom is larger than each individual and calls for communal celebration (fellowship and worship).
4) “Everyone had to eat the meat” – Redemption only occurs to those who partake of it. Consider Jesus’ statement in John 6:47-51, “Truly, truly, I say to you, whoever believes has eternal life. I am the bread of life. Your fathers ate the manna in the wilderness, and they died. This is the bread that comes down from heaven, so that one may eat of it and not die. I am the living bread that came down from heaven. If anyone eats of this bread, he will live forever. And the bread that I will give for the life of the world is my flesh.”
5) “all the meat had to be eaten” – The redemption of God is costly and should not be “wasted”.

But the greater value is in preparation for the Messiah. The Messiah was to be one body, broken for all, symbolically eaten by all, in order to help believers in the New Covenant keep aware of their unity as members of the one body. Partial consumption and fragments left over do not appropriately symbolize that body and that unity. The ultimate purpose of the Old Testament Passover instruction is to point forward to Christ, to the purpose of his death, memorialized in the ritual of the Lord’s Supper that now replaces the Passover, and also to the unity of those accepted by him as his people, his body.
Douglas K. Stuart, Exodus, vol. 2, The New American Commentary (Nashville: Broadman & Holman Publishers, 2006), 274.

4 And if the household is too small for a lamb, then he and his nearest neighbor shall take according to the number of persons; according to what each can eat you shall make your count for the lamb.

5 Your lamb shall be without blemish, a male a year old. You may take it from the sheep or from the goats,

“without blemish” -A blemished animal would taste the same as one without blemish. God is emphasizing something in this statement which should point all who participated beyond the meal itself to what the meal ultimately symbolized-the perfect God, providing perfect redemption.

“Behold, the Lamb of God, who takes away the sin of the world!” Jn 1:29.
“For it was indeed fitting that we should have such a high priest, holy, innocent, unstained, separated from sinners, and exalted above the heavens. He has no need, like those high priests, to offer sacrifices daily, first for his own sins and then for those of the people, since he did this once for all when he offered up himself. For the law appoints men in their weakness as high priests, but the word of the oath, which came later than the law, appoints a Son who has been made perfect forever.” Heb 7:26–28.

How, then, could an animal help provide perfection for those who consumed it so that they could become acceptable to God? The answer is that it could not, except to the extent that the whole process of eating the animal in obedience to the Passover regulations was an act of faith and obedience, involving faith in God’s gracious provision of the holiness that no human could himself or herself provide and obedience to a process that showed confidence in the true God’s true promises and requirements. From the vantage point of the full overview of the plan of redemption designed by God before he even created human beings, Jesus of Nazareth was to be young at the time of his death, male of course, and perfect—free from defect before God. His sinlessness qualified him and him alone to be the lamb of God, a human lamb rather than an animal of the flock, and yet a lamb in the sense of one meeting the criteria for the Passover meal.
Douglas K. Stuart, Exodus, vol. 2, The New American Commentary (Nashville: Broadman & Holman Publishers, 2006), 275.

6 and you shall keep it until the fourteenth day of this month, when the whole assembly of the congregation of Israel shall kill their lambs at twilight.

7 “Then they shall take some of the blood and put it on the two doorposts and the lintel of the houses in which they eat it.

The emphasis now falls, not on the animal, but the importance of it’s blood. Note the redeeming aspect of shed blood highlighted here and consider: 
Jesus’ words before his crucifixion, “for this is my blood of the covenant, which is poured out for many for the forgiveness of sins.” Mt 26:28.

or the author of Hebrews, “
Indeed, under the law almost everything is purified with blood, and without the shedding of blood there is no forgiveness of sins.” Heb 9:22.

What can wash away my sin?

Nothing but the blood of Jesus;

What can make me whole again?

Nothing but the blood of Jesus.

Oh! precious is the flow

That makes me white as snow;

No other fount I know,

Nothing but the blood of Jesus.

“put it on the two doorposts and the lintel of the houses” -Note that the blood was smeared on the doorframe even before the Passover meal was eaten; this may be an instance of first things first, that is, that deliverance from death is the primary interest of these instructions and proper memorializing of the exodus the less crucial concern.
Douglas K. Stuart, Exodus, vol. 2, The New American Commentary (Nashville: Broadman & Holman Publishers, 2006), 276.

8 They shall eat the flesh that night, roasted on the fire; with unleavened bread and bitter herbs they shall eat it.

“They shall eat the flesh” -Note John 6:51 quoted above.
 See also:
”Whoever feeds on my flesh and drinks my blood abides in me, and I in him.” Jn 6:56.

9 Do not eat any of it raw or boiled in water, but roasted, its head with its legs and its inner parts.

10 And you shall let none of it remain until the morning; anything that remains until the morning you shall burn.

11 In this manner you shall eat it: with your belt fastened, your sandals on your feet, and your staff in your hand. And you shall eat it in haste. It is the Lord’s Passover.

The dress and haste of eating was to demonstrate their readiness and the immediacy of their departure from Egypt.

Do not overlook the faith involved in preparation and eating with haste. Their willingness to eat in a manner that suggested immediate departure was a manner of eating in faith believing, God was to act suddenly and immediately on their behalf. What an act of faith after considering their years of slavery (430yrs) and Pharaoh’s recent stubborn refusal to release Israel from Egyptian control even after the other 9 plagues.

12 For I will pass through the land of Egypt that night, and I will strike all the firstborn in the land of Egypt, both man and beast; and on all the gods of Egypt I will execute judgments: I am the Lord.

“I will execute judgments: I am the Lord” -This final plague would demonstrate Yahweh’s sovereignty and power over the false god’s of Egypt.

13 The blood shall be a sign for you, on the houses where you are. And when I see the blood, I will pass over you, and no plague will befall you to destroy you, when I strike the land of Egypt.

The blood on the doorposts showed acceptance of God’s plan for rescue and trust in his word. After all, the sight of dried blood by itself had no power to deter death; it was only as the dried blood painted on the top and sides of the door was a testimony to the faith of the inhabitants in Yahweh that it had its efficacy. Thus the statement, “When I see the blood, I will pass over you”—in other words, I will spare all those who show that they have placed their faith in me.
Douglas K. Stuart, Exodus, vol. 2, The New American Commentary (Nashville: Broadman & Holman Publishers, 2006), 278.