I. Two kinds of firstborn
(1) יֵשׁ בְּכוֹר לַנַּחֲלָה וְאֵינוֹ בְכוֹר לַכֹּהֵן, (2) בְּכוֹר לַכֹּהֵן וְאֵינוֹ בְכוֹר לַנַּחֲלָה, (3) בְּכוֹר לַנַּחֲלָה וְלַכֹּהֵן, (4) יֵשׁ שֶׁאֵינוֹ בְכוֹר לֹא לַנַּחֲלָה וְלֹא לַכֹּהֵן.
אֵיזֶהוּ בְּכוֹר לַנַּחֲלָה וְאֵינוֹ בְכוֹר לַכֹּהֵן? הַבָּא אַחַר הַנְּפָלִים שֶׁיָּצָא רֹאשׁוֹ חַי, וּבֶן תִּשְׁעָה שֶׁיָּצָא רֹאשׁוֹ מֵת, - וְהַמַּפֶּלֶת כְּמִין בְּהֵמָה חַיָּה וָעוֹף, דִּבְרֵי רַבִּי מֵאִיר. וַחֲכָמִים אוֹמְרִים, עַד שֶׁיְּהֵא בוֹ מִצּוּרַת הָאָדָם...
מִי שֶׁלֹּא הָיוּ לוֹ בָנִים וְנָשָׂא אִשָּׁה שֶׁכְּבָר יָלְדָה, עוֹדָהּ שִׁפְחָה וְנִשְׁתַּחְרְרָה, עוֹדָהּ נָכְרִית וְנִתְגַּיְּרָה, מִשֶּׁבָּאת לְיִשְׁרָאֵל יָלְדָה, בְּכוֹר לַנַּחֲלָה וְאֵינוֹ בְכוֹר לַכֹּהֵן. רַבִּי יוֹסֵי הַגְּלִילִי אוֹמֵר, בְּכוֹר לַנַּחֲלָה וְלַכֹּהֵן, שֶׁנֶּאֱמַר (שמות יג), "פֶּטֶר כָּל רֶחֶם בִּבְנֵי יִשְׂרָאֵל," עַד שֶׁיִּפְטְרוּ רֶחֶם מִיִּשְׂרָאֵל.
There are those who are: (i) Firstborn for inheritance but not firstborn for the priest; (ii) firstborn for the priest but not firstborn for inheritance; (iii) firstborn for inheritance and for the priest; (iv) firstborn for neither inheritance nor the priest.
Which is a firstborn for inheritance but not firstorn for the priest? One who comes after: a miscarried fetus whose head came out alive; a full-term fetus whose head came out dead;—and a miscarried fetus that looks like some kind of beast, animal or bird—words of Rabbi Meir; but the Sages say: Only when it has the likeness of a person…
One who didn’t have children and married a woman that had already given birth; [or she had children when] she was still a slave and then was freed; [or when] she was still a Gentile and she converted, and when she became Jewish she gave birth [again]—[this child] is a firstborn for inheritance but not a firstborn for the priest. Rabbi Yose Ha-Gelili says: A firstborn for inheritance and the priest, as it is said, “The opening of every womb among the Israelites” (Exodus 13:2)—when the womb is opened from a Jew.
II. Whose firstborn is it anyway?
(1) God spoke to Moses: (2)“Consecrate to me every firstborn opening of every womb among the Israelites—person and beast, it is Mine.”
(11) “And when God has brought you into the land of the Canaanites, as God swore to you and to your fathers, and has given it to you, (12) you shall set apart for God every first issue of the womb: every male firstling that your cattle drop shall be God’s. (13) But every firstling ass you shall redeem with a sheep; if you do not redeem it, you must break its neck. And you must redeem every firstborn male among your children. (14) And when, in time to come, your son asks you, saying, ‘What does this mean?’ you shall say to him, ‘It was with a mighty hand that God brought us out from Egypt, the house of bondage. (15) When Pharaoh stubbornly refused to let us go, God slew every firstborn in the land of Egypt, the firstborn of both human and beast. Therefore I sacrifice to God every first male issue of the womb, but redeem every firstborn among my sons.’ (16) “And so it shall be as a sign upon your hand and as a symbol on your forehead that with a mighty hand God freed us from Egypt.”
(28) You shall not put off the skimming of the first yield of your vats. You shall give Me the firstborn among your children. (29) You shall do the same with your cattle and your flocks: seven days it shall remain with its mother; on the eighth day you shall give it to Me. (30) You shall be holy people to Me: you must not eat flesh torn by beasts in the field; you shall cast it to the dogs.
(11) God spoke to Moses, saying: (12) I hereby take the Levites from among the Israelites in place of all the firstborn, the first issue of the womb among the Israelites: the Levites shall be Mine. (13) For every firstborn is Mine: at the time that I smote every firstborn in the land of Egypt, I consecrated every firstborn in Israel, man and beast, to Myself, to be Mine, God’s.
(15) The first issue of the womb of every being, man or beast, that is offered to God, shall be yours; but you shall have the firstborn of man redeemed, and you shall also have the firstling of unclean animals redeemed. (16) Take as their redemption price, from the age of one month up, the money equivalent of five shekels by the sanctuary weight, which is twenty gerahs.
(א) וַיְדַבֵּ֥ר יקוק אֶל־מֹשֶׁ֥ה לֵּאמֹֽר׃ (ב) דַּבֵּ֞ר אֶל־בְּנֵ֤י יִשְׂרָאֵל֙ וְאָמַרְתָּ֣ אֲלֵהֶ֔ם אִ֕ישׁ כִּ֥י יַפְלִ֖א נֶ֑דֶר בְּעֶרְכְּךָ֥ נְפָשֹׁ֖ת לַֽיקוק׃
(1) God spoke to Moses, saying: (2) Speak to the Israelite people and say to them: When anyone explicitly vows to God the equivalent for a human being…
III. Firstborn and family dynamics
(15) If a man has two wives, one loved and the other hated, and both the loved and the hated have borne him sons, but the firstborn is the son of the hated one—(16) when he wills his property to his sons, he may not treat as firstborn the son of the loved one in disregard of the son of the hated one who is older. (17) Instead, he must recognise the firstborn, the son of the hated one, and allot to him a double portion of all he possesses; since he is the first fruit of his vigour, the birthright is his due.
אמר רבי שמעון בן לקיש: פדחת פוטרת בכל מקום, חוץ מן הנחלה,
מאי טעמא? דכתיב "יכיר".
ור' יוחנן אמר: אפי' לנחלה.
בכל מקום לאיתויי מאי?
לאיתויי הא דתנו רבנן: גיורת שיצאה פדחת ולדה בהיותה נכרית, ואח"כ נתגיירה אין נותנין לה ימי טומאה וימי טהרה, ואינה מביאה קרבן לידה.
מיתיבי: יכיר - זו הכרת פנים, ואיזו היא הכרת פנים? פרצוף פנים עם החוטם!
תני: עד החוטם.
תא שמע: אין מעידים אלא על פרצוף פנים עם החוטם!
תני: עד החוטם...
שאני עדות אשה דאחמירו בה רבנן...
ואיבעית אימא: [מז ע"א] "יכיר" לחוד, והכרת פנים לחוד.
Said Rabbi Shimon ben Lakish: The forehead exempts in all cases—except for inheritance.
What is the reason? As it is written, “He must recognise.”
But Rabbi Yohanan said: Even for inheritance.
“In all cases”—to include what?
To include this that our rabbis taught: A female convert [whose son’s] forehead comes out and she gives birth while still a Gentile, and afterwards she converts—they do not give her the days of her impurity or the days of her purity, nor does she bring a birth sacrifice.
They objected: “He must recognise”—this is facial recognition. And what is facial recognition? The distinctive features of the face with the nose!
He recited: Until the nose.
Come and learn: They do not testify [about a woman that she can get remarried after her husband’s death] except based on [seeing the husband’s] distinctive features of the face with the nose!
He recited: Until the nose…
Testimony for a wife is different since the rabbis were stringent on it…
Or if you want, another answer: “He must recognise” and “facial recognition” are unrelated laws.
(2) Say to the Israelites: A woman, when she gives birth to a male, she will be impure for seven days like the days of her menstrual impurity she is impure, (3) and on the eighth day his foreskin will be circumcised. (4) For 33 days she will sit in days of purity, but she should not touch any holy items and should not come to the sanctuary until her days of purity are completed. (5) And if she gave birth to a female, she will be impure for two weeks like her menstrual impurity, and will sit for 66 days for her blood of purity. (6) As the days of her purity are completed, whether for a son or for a daughter, she will bring a yearling sheep for a burnt offering and a dove or turtledove for a purification offering to the Tent of Meeting, to the priest.
[הַמַּפֶּלֶת מִין בְּהֵמָה, חַיָּה וָעוֹף, בֵּין טְמֵאִין בֵּין טְהוֹרִים, אִם זָכָר, תֵּשֵׁב לְזָכָר. וְאִם נְקֵבָה, תֵּשֵׁב לִנְקֵבָה.
וְאִם אֵין יָדוּעַ, תֵּשֵׁב לְזָכָר וְלִנְקֵבָה, דִּבְרֵי רַבִּי מֵאִיר. וַחֲכָמִים אוֹמְרִים, כֹּל שֶׁאֵין בּוֹ מִצּוּרַת אָדָם, אֵינוֹ וָלָד:]
רבי יוחנן: הלידה הזאת ככל הלידות שבתורה - מה הלידות שבתורה עד שיצא ראשו ורובו, וזו עד שיצא ראשו ורובו.
ר' שמעון בן לקיש אמ': משונה היא הלידה הזאת מכל הלידות שבתורה - כל הלידות שבתורה עד שיצא ראשו ורובו, וזו עד שתצא הכרת פניו.
[A miscarried fetus that looks like a kind of beast, animal or bird—whether impure or pure—if it is male, she sits for a male; if it is female, she sits for a female.
And if it is unknown, she sits for a male and for a female—words of Rabbi Meir.
But the Sages say: Anything that doesn’t have the likeness of a man is not a birth.]
Rabbi Yohanan: This birth is like all the other births in the Torah—just as the births in the Torah [count] from when its head and most of its body [comes out], [so too] this one [counts] from when its head and most of its body [comes out].
Rabbi Shimon ben Lakish said: This birth is different from all other births in the Torah—all other births in the Torah [count] from when its head and most of its body [comes out], but this one [counts] from when [enough] comes out [for] facial recognition.