What is considered to be "firstborn"?

Question

This is probably a bit pedantic and beside-the-point, but here goes: in Exodus 12 (I am reading the Jewish Publication Society translation), we have:

12 For I will go through the land of Egypt in that night, and will smite all the first-born in the land of Egypt, both man and beast; and against all the gods of Egypt I will execute judgments: I am the LORD. 13 And the blood shall be to you for a token upon the houses where ye are; and when I see the blood, I will pass over you, and there shall no plague be upon you to destroy you, when I smite the land of Egypt.

Later:

29 And it came to pass at midnight, that the LORD smote all the firstborn in the land of Egypt, from the first-born of Pharaoh that sat on his throne unto the first-born of the captive that was in the dungeon; and all the first-born of cattle. 30 And Pharaoh rose up in the night, he, and all his servants, and all the Egyptians; and there was a great cry in Egypt; for there was not a house where there was not one dead.

I was wondering about what is meant to be considered "the firstborn" in this context, beyond possibly referring to male children - this detail is something I'm not sure of, since I have absolutely no idea where I picked it up. (My guess - from reading Wikipedia - is that this should be correct.) Moreover, from the second passage, this would suggest that this applies to the firstborn of each intra-family generation to me. However:

• I'm merely making an educated guess here. Am I correct on the above points? It strikes me as slightly weird for, for instance, a firstborn elderly man to die, but this is something that I can "live" with.

• Is there any indication (whether textual, or through some sort of tradition) if this applies to the firstborn of a father, or to that of a mother? Naturally in many cases, this shouldn't matter, but in others (e.g. remarriage of widowed individuals) it does.

These aren't really issues that affect the meaning of the text for me, from a "moral" angle, but I'm curious about whether or not some specifics are ever actually addressed.

Answer 1

Due to Egyptian immorality, there were actually a lot of firstborns. All of these were counted:

• Firstborn of the mother
• Firstborn of the father
• Male
• Female
• Oldest in the house, even if not a firstborn
• All Egyptian firstborns, even in other countries
• Firstborns of other nationalities currently in Egypt

Rashi to Ex. 12:30, s.v. כי אין בית אשר אין שם מת and Rashi Ex. 12:12 s.v. כל בכור בארץ מצרים.

This meant that there would even be multiple deaths per house. (Rashi to Ex. 12:33)

Answer 2

I had the same question so, instead of asking a duplicate, I'm placing my research here.

Exodus 11:4-5:

So said the Lord, At the dividing point of the night, I will go out into the midst of Egypt, and every firstborn in the land of Egypt will die, from the firstborn of Pharaoh who sits on his throne to the firstborn of the slave woman who is behind the millstones, and every firstborn animal.

Exodus 12:12:

I will pass through the land of Egypt on this night, and I will smite every firstborn in the land of Egypt, both man and beast, and upon all the gods of Egypt will I wreak judgments I, the Lord.

Exodus 12:29:

It came to pass at midnight, and the Lord smote every firstborn in the land of Egypt, from the firstborn of Pharaoh who sits on his throne to the firstborn of the captive who is in the dungeon, and every firstborn animal.

Exodus 12:29 - Rashi:

From the firstborn of Pharaoh: Pharaoh, too, was a firstborn, but he remained [alive] of the firstborn. Concerning him, He [God] says: “But, for this [reason] I have allowed you to stand, in order to show you My strength” (Exod. 9:16) at the Red Sea. — [from Mechilta]

Exodus 12:30:

And Pharaoh arose at night, he and all his servants and all the Egyptians, and there was a great outcry in Egypt, for there was no house in which no one was dead.

Exodus 12:30 - Rashi:

For there was no house in which no one was dead: If there was a firstborn, he was dead. If there was no firstborn, the oldest household member was called the firstborn, as it is said: “I, too, shall make him [David] a firstborn” (Ps. 89:28) (Tanchuma Buber 19). [Rashi explains there: I shall make him great.] Another explanation: Some Egyptian women were unfaithful to their husbands and bore children from bachelors. Thus they would have many firstborn; sometimes one woman would have five, each one the firstborn of his father (Mechilta 13:33).