Why does the Torah write, "Hu v'Chol Avadav"?
Rashi: It teaches us that, a. On that night, Pharaoh was the first to rise, at midnight - unlike the way of kings, who generally rise after three hours in the day (at around nine a.m.); b. Pharaoh then went around to the houses of his servants, to arouse them and inform them of the calamity that had befallen them. 1
See Sifsei Chachamim.
Surely there were houses in which the Bechor had already died! How can it be that there was no house without a Meis?
Rashi: If there was no firstborn in the house, then the oldest member of the family died. 1
Da'as Zekenim #1 and Hadar Zekenim #1 (citing the Sifri): It was customary among the Egyptians, that when a firstborn died, they made a bust of him. Those images now melted, and it was as hard for them as the day that they (the firstborn) had died.
Da'as Zekenim #2 and Hadar Zekenim #2: Mice dug up the firstborn from where they were buried, and dragged them [to the houses].
Rosh: The Egyptians buried their dead in their houses, and dogs dug up the corpses and dragged them from house to house.
Rashi: And we find the word 'firstborn' used in this way in Tehilim 89:28.
QUESTIONS ON RASHI
Rashi writes: "For there was no house without [someone] dead - ... If there was no firstborn, the most important person in the house was the Bechor...." According to the Midrash, the custom in Egypt was that when a Bechor died, they would erect his image in their home. When Makas Bechoros struck, that image became defaced. The dogs then invaded the burial caves, and dragged out the dead firstborn themselves. Why did the Egyptians have such a custom? Why were their firstborn stricken, even after their death?
Maharal (Gevuros Hashem Ch. 37, p. 140): The Egyptians' primary power was their firstborn; they worshipped Mazal Taleh, the first of the twelve zodiac constellations. The Mitzrim were base Chomer; and Chomer is first (in relation to Tzurah). 1 Thus, they would erect an image of their deceased firstborn, as it represented their deity. Part of Makas Bechoros was the destruction of the Egyptian idols -- which of course were just as "dead."
Maharal (Gevuros Hashem Ch. 4, p. 140): The terms Chomer and Tzurah appear frequently in Maharal. To illustrate, Chomer is the metal from which a knife is made, and Tzurah is the shape that metal takes to fulfill its specific function (to cut). Thus, Chomer always precedes Tzurah. The Mitzrim were 'Reishis' (first) only in the sense that they were base Chomer (physicality). They had unlimited means and potential, yet they had no boundaries or obligations towards fulfilling any purpose. This explains why they were steeped in immorality. (Compare to Shemos 1:1:2.8:1 and 1:1:2.9:1 with their notes. Also see 12:13:2.4:1** about the conceptual distinction between the Egyptian firstborn, and Am Yisrael's status as "Bechor" (see 4:22). Also see 12:30:2.2:2 and its note; 12:12:2.2; 12:29:3.3:1; and 8:22:1.2:1.)
Rashi writes: "... Alternatively, the Egyptian women would commit adultery... and have many firstborn, even five! - each one a firstborn to his father." Since a father's firstborn was also included in the Makah, why, when we commemorate this event by sanctifying our own firstborn (13:2), does the Mitzvah include only a mother's firstborn?
Gur Aryeh #1: The primary Makah was against the "Peter Rechem," the child born first to its mother; and furthermore, paternity is not ascribed by Nochrim (Sanhedrin 58b). Nevertheless, the Makah then extended to include anyone who could be referred to as a "Bechor" - such as the first offspring of a father. (As Rashi writes, it extended even further, to include even the greatest member of the household in the absence of any Bechor.) 1
Gur Aryeh #2: Conceptually, the sanctity of a Bechor stems from its being first to emerge into existence. A mother's firstborn is 'first' in his emergence into the world - and this causes the sanctity. 2 Paternity does not (directly) bring something new into existence; at most, being a father's firstborn means being his 'initial strength' 3 - significant vis a vis that father only.
Compare Maharal (Gevuros Hashem Ch. 37, p. 140) - There were (other) peripheral aspects of Makas Bechoros, such as the "Mashchis" (12:13); and Bnei Yisrael were saved from these aspects only in the merit of bringing the Korban Pesach. Nevertheless, the Mitzvah to commemorate Makas Bechoros applies only to those firstborn who were definitely included in the Makah - the mothers' firstborn.
Also see Maharal (in Gur Aryeh to 4:22, and Gevuros Hashem Ch. 29, p. 113) - That which is 'Reishis' (and thus the root for all that follows) becomes sanctified. He writes that basic Chomer which has not assumed a Tzurah, can be said to precede Chomer that has taken on somewhat of a form (see the preceding question, 12:30:2.1:1*, for more on these terms). Perhaps we may explain, that being the firstborn of a father has no direct physical expression, and thus no sanctity takes hold. (EK) Also refer to Shemos 4:22:1:4, 4:22:1:5, 4:22:1:6 and notes; as well as 13:13:1.01:1*.
As in Bereishis 49:3.
