Shearing, Plucking, and the Wool of a Firstborn

How the Gemara defines shearing and plucking, permitting manual hair removal for slaughter while permanently forbidding shed wool.

The Prohibition of Shearing Consecrated Animals

The Torah commands that an owner may not work a firstborn ox nor shear a firstborn sheep. The Gemara applies each ban to both animals by linking the clauses together. Consequently, an ox may not be shorn, and a sheep may not be worked.

The Gemara determines that תולש (plucking hair) is fundamentally distinct from גוזז (shearing with an implement). Rambam codifies that shearing any sacrificial animal incurs lashes by biblical law, but manual plucking is not considered shearing under Torah law. Shulchan Arukh rules that a בכור (firstborn animal) is strictly forbidden for shearing and labor.

Plucking Hair for Slaughter and Blemish Inspection

When preparing to slaughter a בכור, an individual must expose the neck so the slaughtering knife can cut cleanly. The Gemara clarifies that clearing space is permitted only by hand, whereas using an implement is prohibited because it resembles standard shearing.

The Gemara further asks whether one may pluck wool to inspect a מום (blemish) לכתחילה (ab initio). Rabbi Yirmeya proves from a baraita that one may indeed pluck wool ab initio to show an obscured blemish to a Sage. Rambam rules that one may pluck hair ab initio to display a blemish to an expert. Maran rules in Shulchan Arukh that one may pluck hair by hand for slaughter or inspection, but never with a tool.

אָמַר רַב אָשֵׁי אָמַר רֵישׁ לָקִישׁ: לֹא שָׁנוּ אֶלָּא בַּיָּד, אֲבָל בִּכְלִי — אָסוּר.

Rav Ashi says that Reish Lakish says: They taught that this is permitted only if one plucks the hair by hand, but if he does it with a tool it is prohibited. (Bekhorot 25a:13)

The Permanent Prohibition on Detached Wool

The Mishnah debates the status of wool that shed or was plucked from a blemished בכור during its lifetime and stored away. Although ritual slaughter permits the attached fleece together with the animal's meat, the Sages rule that detached wool remains forbidden.

The Gemara explains that this ban is a rabbinic decree lest the owner postpone slaughtering the animal to accumulate shed wool. Rambam rules that detached wool remains forbidden from benefit even after the animal is slaughtered due to its blemish. Shulchan Arukh codifies that wool shed or plucked during life remains permanently forbidden, and subsequent slaughter never permits it.

אוֹ אֲפִילוּ נָשַׁר הַצֶּמֶר מֵעַצְמוֹ אָסוּר בַּהֲנָאָה לְעוֹלָם לֹא שְׁנָא מֵת מֵעַצְמוֹ ל"שׁ שְׁחָטוֹ אַחַ"כּ

Or even if the wool fell out on its own, it is forbidden from benefit forever, no matter whether it died on its own or he slaughtered it afterward. (Shulchan Arukh, Yoreh De'ah 308:1)

Plucking Feathers and Shearing the Red Heifer

The Gemara analyzes exceptions to define the boundaries of shearing. Plucking a bird feather on Shabbat constitutes the forbidden labor of shearing because plucking is the natural manner of removing feathers. In contrast, one may shear black tips on a פרה אדומה (red heifer) with scissors without transgression.

Rambam rules that plucking a bird's feather on Shabbat is a derivative of shearing, trimming the tip is cutting, and smoothing down is erasing. For the red heifer, Rambam rules that clipping black tips is permitted because the intent is solely to qualify the heifer, not to harvest fleece.

While one may pluck hair by hand to inspect or slaughter a בכור, any wool detached during its lifetime remains permanently forbidden from benefit.

Learn Bekhorot 25 on Super Daf