The Blemished Firstborn: An Unprecedented Priestly Gift

The Gemara examines why a blemished firstborn is awarded to the priest, prompting commentators to debate what makes this gift unique across the Torah.

The Fate of a Blemished Firstborn

The Torah requires every owner to sanctify the male בכור (firstborn animal) of a kosher herd or flock. When the animal is a תם (unblemished animal), it is sacrificed upon the altar in Jerusalem, and its flesh is eaten by the כהנים (priests).

However, sacrificial law forbids offering an animal with a permanent physical blemish on the altar. If a בכור is born with a blemish, or develops one before it can be sacrificed, its status changes.

Does the animal remain with its Israelite owner, or must it still be delivered to the כהן? The Gemara notes that Scripture must explicitly teach that a בכור בעל מום (blemished firstborn) belongs to the כהן, as this rule cannot be assumed on its own.

Two Derivations in the Academy

How do the Sages derive that a בכור בעל מום belongs to the כהן? The Gemara presents a debate over the phrasing of the verse in Parashat Korach,.

Rav derives the law from the plural word וּבְשָׂרָם ("and their flesh"). This plural formulation teaches that the verse encompasses both unblemished and blemished animals as priestly gifts.

The school of Rav disagrees, arguing that וּבְשָׂרָם merely refers to the firstborns of all Israel,. Instead, they derive this rule from the supplementary clause לְךָ יִהְיֶה ("it shall be yours"), which grants the blemished animal directly to the כהן.

הַאי ״יִהְיֶה לָּךְ״ — לִימֵּד עַל בְּכוֹר בַּעַל מוּם שֶׁנּוֹתְנוֹ לְכֹהֵן, שֶׁלֹּא מָצִינוּ לוֹ בְּכׇל הַתּוֹרָה כּוּלָּהּ.

This phrase: 'It shall be yours,' teaches with regard to a blemished firstborn that the owner must give it to the priest, for we have not found this in the entire Torah. (Bekhorot 28a:3)

Rashi: An Unstated Priestly Gift

The Gemara notes that Scripture had to explicitly state this law because "we have not found it in the entire Torah". Rashi and Tosafot disagree over the meaning of this statement.

Rashi explains the phrase at its simplest level: nowhere else does the Torah instruct an owner to give a blemished firstborn to a כהן.

Without this specific scriptural amplification, we would assume that a blemished animal remains ordinary private property. The verse therefore establishes an unstated priestly gift that has no other statutory basis in the biblical text.

שלא מצינו בכל התורה כולה - שיתננו לכהן אלא מרבויא דהאי יהיה לך נפקא

'For we have not found in the entire Torah'—that he must give it to a priest, but rather it is derived from the inclusion of this phrase, 'it shall be yours.' (Rashi on Bekhorot 28a:3:1)

Tosafot: Priestly Portions Without an Altar

Tosafot (Rabbeinu Yitzchak) rejects Rashi's explanation, noting that many laws in the Torah rely on a single derivation without the Gemara calling them unprecedented.

Instead, Tosafot identifies a fundamental principle of sacrificial law: priests receive their portions only as table-companions of the altar. In a חטאת (sin offering) or an אשם (guilt offering), when a blemish disqualifies the animal, the priests forfeit their share along with the altar.

The בכור is entirely unique across the Torah because the כהן receives the animal even though the altar receives nothing,. A special derivation was necessary to establish a priestly offering that completely bypasses the altar.

דחטאת ואשם שהם לכהן כשקריבין למזבח אם הוממו שהמזבח מפסיד חלקו מפסיד גם לכהן אבל בכור אפילו בעל מום דכהן הוא

For with a sin offering and a guilt offering, which belong to the priest when sacrificed, if they become blemished such that the altar loses its portion, the priest also loses his portion; yet with a firstborn, even a blemished one belongs to the priest. (Tosafot on Bekhorot 28a:3:1)

The Halachic Codification

The halacha is decided according to the Talmudic consensus that every בכור בעל מום must be given to a כהן,.

The Rambam codifies that whether an animal was born blemished or developed a blemish later, it belongs to the כהן.

Because it is not offered upon the altar, it becomes the priest's private property (נכסי כהן). The כהן may eat it in any location, sell it, or feed it to anyone he chooses.

While disqualifying blemishes cause kohanim to forfeit their share in all other sacrifices, a blemished firstborn belongs entirely to the kohen as personal property.

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