וה' הכה כל בכור בארץ מצרים, “and G’d slew every firstborn in the land of Egypt, etc.” G’d carried out His retribution on the Egyptians according to the principle of מדה כנגד מדה, tit for tat, the punishment being fitted to the crime committed. This is why the 10 plagues were summed up in the abbreviated form of דצ'ך עד'ש באח'ב. The Egyptians’ principal source of faith was the dependability of the river Nile as their water supply, as the lifeline. It irrigated all their fields and they had made the Israelites slave in order to draw the water from the river. G’d therefore turned the river into blood. Seeing that the Egyptians used to awaken their Jewish slaves in the middle of the night and impose most onerous duties on them, the river was told to produce frogs in swarms which would invade the Egyptian houses and cause misery and revulsion for the Egyptians. The frogs even invaded the entrails of the Egyptians causing them distress (Shemot Rabbah 10,6). Seeing that the Egyptians had prevented the Israelites from bathing and washing themselves, the third plague, כנים, lice, was meant to demonstrate to the Egyptians what it means to be denied water to wash yourself and for one’s body to be infested with lice and other insects The Egyptians would demand from their Jewish slaves to go out into the forest and hunt wild animals for them, a dangerous undertaking. They experienced what it means to be surrounded by wild animals who do not respect civilization when G’d let loose the fourth plague, the invasion of their cities by wild beasts. The Egyptians had forced the Israelites to look after their livestock. G’d therefore afflicted the livestock with pestilence so that they would realize they had had no right to force the Israelites to perform such duties. The Egyptians had made the Israelites carry hot water for them to their bath houses. In retaliation, G’d made their skin break out in boils to remind them that they had not had the right to impose these kinds of duties on the Israelites. In retaliation for the Egyptians stoning Israelites, G’d brought on the plague of hailstones. In retribution for the Egyptians having forced the Israelites to work their vineyards, G’d made the locust ruin the vineyards. Seeing the Egyptians frequently put innocent Israelites in dark prisons G’d brought on the plague of darkness. Seeing they entertained plans of killing the Israelites who have been described as G’d’s firstborn (4,22), G’d punished them by killing their firstborn instead. [The various accusations leveled against the Egyptians by our author are all supported by Midrashim. Ed.]
The Significance of the Tenth, Rabbi Dr. Ismar Schorsch (JTS)
The tenth plague finally shatters Pharaoh's resistance. The sudden death in a single night of "all the first-born in the land of Egypt from the first-born of Pharaoh who sat on the throne to the first-born of the captive who was in the dungeon, and all the first-born of the cattle" is singularly devastating and beyond all natural explanation (Exodus 12:29). It is, in a word, a miracle, attributable only to the awesome power of Moses' God. Pharaoh is not only vanquished but also converted. As he urges Moses and Aaron to lead their untouched slaves out of Egypt immediately, leaving nothing behind, and to worship their Lord, he adds desperately if sheepishly, "And may you bring a blessing upon me also! (Exodus 12:32)"
God could have finished Pharaoh off with any number of knockout punches. Is there a reason why God chose to deliver that final blow by killing the first-born?
[Makat Bechorot] links the status of Israel as God's first-born son to the death of the first-born of Egypt. The exodus is perceived by the Torah as an act of adoption and rejection. The display of divine concern for Israel creates a covenantal relationship between God and a relatively new and insignificant people, even as it signifies the repudiation of an ancient and world-class civilization. The antiquity of a nation counts for little in the divine economy.The converse of Israel's chosenness, the tenth plague is the final expression of the motif that dominated the book of Genesis. Throughout we saw demotion and derogation of the first-born son, from Cain to Reuben. God's favor consistently fell on younger siblings. Not birth but character is the decisive quality for leadership. The shift from primogeniture to morality allows for religious meritocracy and justifies God's selection of Israel. The death of Egypt's first-born symbolizes a revolution in religious thought.
Where is the Justice in the Tenth Plague? By Ezra Sivan (Lehrhaus)
There is one last feature of the rigid Egyptian social classifications that seems important if we are to understand the tenth plague: the status of the firstborn. In short, veneration of the firstborn seems fundamental to the Torah’s account of Egyptian society. As R. Ari Kahn notes (building on R. Naphtali Zvi Yehuda Berlin and R. J.B. Soloveitchik), “Egyptian culture was built on a hierarchical system of primogeniture, in which the firstborn ruled the family by controlling the younger siblings who in turn, controlled the lower classes, who in turn controlled the slaves.” Accordingly, just after the text describes the seating arrangements at Joseph’s home, it tells us that Joseph made sure to seat the brothers according to their birth order. The brothers were “amazed”—apparently because Joseph could “divine” their birth order (cf., Genesis 44:15). Another implication is that the brothers would otherwise not have emphasized their birth order. This may be in keeping with the Torah’s larger project of suggesting that the firstborn son (Cain, Ishmael, Esau, Reuben, Aaron) does not deserve as much honor as was traditionally supposed.
While Joseph was just playing God (he knew the birth order because he was actually a member of the family), God Himself was responsible for divining birth order in the tenth plague. In that respect, the tenth plague was the climax of the plagues in that it demonstrated God’s ability and willingness to make distinctions as He saw fit and in direct subversion of the pretense that Pharaoh was the master of natural and social order. It is easy to make distinctions based on visible differences such as place of residence (plagues 4 and 7) or ethnicity (plagues 5 and 9); it is quite another thing to distinguish between household (and barnyard) members based on when they were born.
In addition, beyond demonstrating God’s omniscience and mastery, the tenth plague also attacked the false god of arbitrary social hierarchies. Given the Egyptian veneration of the firstborn, and given the importance of Pharaoh’s firstborn in perpetuating the system more generally, these are natural targets for an effort to “collapse the (Egyptian) pyramid scheme.” The Torah’s emphasis on the range of statuses hit by the plague dovetails with this theme. What better way to show that social distinctions are meaningless than to have every single household—from the top to the very bottom of the Egyptian social pyramid, including even slaves, captives, and livestock—suffer from the same plague? All are equal before God.
Nine Plagues and One More - The Uniqueness of the Tenth Plague, Rabbi Dr. Isaac Kraus (Bar Ilan)
This plague differs [from the other nine] philosophically. Most of the verses on the plague of the first-born concern the Israelites' preparations to protect themselves from this scourge, and not a description of the plague itself. This need for protection demands an explanation. Could the Lord not distinguish between the homes of the Israelites and those of the Egyptians? Why would He need a sign on the doorways of their homes? Indeed, Rabbi Ishmael asked in the Mekhilta (Bo, 7):
Is not everything known to Him, as it is said, "He ... knows what is in the darkness, and light dwells with Him" (Dan. 2:22)? And it is said, "Darkness is not dark for You" (Ps. 139:12). So what is the Torah trying to teach us by saying, "when I see the blood" (Ex. 12:13)?
Similarly Rabbi Isaac Abarbanel asked in his commentary (Ch. 12, fifth question):
The words, "when I see the blood I will pass over you," seem to indicate that if He did not see it, that home would be struck by the plague. But how could that be? For the Egyptians deserved the plague for the evil they had done the Israelites, but why should the Israelites be put to death? What had they done? If the plague were by divine providence, how could it strike the righteous along with the wicked? Moreover, in the other plagues that were carried out by intermediaries the Lord discriminated between the Israelites and the Egyptians, so that they were not punished along with them, yet they had not put a sign on their homes? Whey, then, with this plague was discriminating made conditional on the sign of blood on the houses, when the one carrying it out was the Omniscient, Blessed be He?
The answer to the questions posed by Rabbi Ishmael and Rabbi Abarbanel points to the plague of the first-born being unique in its objective. True, it struck at the Egyptians and it was the blow that led to the release of the Israelites; but the Lord had many ways of bringing about the liberation of the people of Israel, so why did He choose precisely this way? It seems that this plague was designed not only to bring the Egyptians to surrender, but first and foremost to affect the people of Israel. In the plague of the first-born, also the people of Israel were put to the test.
In Midrash Tehillim (Buber ed., Psalm 15) it is claimed, "Both these and those worshipped pagan gods." So wherein was Israel better? To this question, where was the merit of the Israelites? Rabbi Ishmael in the Mekhilta ( loc. sit.) responded: "So what is the Torah trying to teach us by saying, "when I see the blood" (Ex. 12:13)? None other than that as a reward for the commandment which you keep I shall reveal Myself to you and take mercy on you, as it is said, "I will pass over you'".