Presumptions of Motherhood and Clearing Wool on Bekhorot 24

How nursing establishes maternal identity for firstborn status, the doubt of strange offspring, and the rules of plucking wool for slaughter.

Presumptions of Nursing in Mixed Flocks

The Gemara evaluates how maternal instinct defines the status of offspring. When several mothers give birth overnight unobserved, some having previously calved and some giving birth for the first time, a question arises regarding firstborn consecration. If the males are found nursing from the previously calved mothers and females from the new mothers, must one fear they switched?

Rabban Shimon ben Gamliel teaches that we do not suspect calves switched mothers. An animal does not abandon its own offspring to nurse another. Similarly, if one buys an animal nursing an offspring from a gentile, its future offspring are exempt from firstborn sanctity, because an animal only produces milk and nurses once it has calved.

The Rambam codifies that we presume each mother is nursing its own offspring. Furthermore, an animal purchased while nursing is exempt from firstborn status on future births, even if the young creature resembles another species. Maran rules identically in the Shulchan Arukh: we do not suspect young animals switched, as each animal nurses its own.

אלא הדבר בחזקתו שכל אחת מניקה את בנה

Rather, the matter stands in its presumption that each animal nurses its own offspring. (Shulchan Arukh, Yoreh De'ah 316:5)

An Impure-Looking Newborn Trailing a Kosher Mother

A kosher animal that gives birth to an offspring resembling an impure species produces a kosher offspring, provided the birth was witnessed. The Gemara inquires what happens if a ewe is found in the field with a pig-like creature trailing and nursing from it without witnesses.

Rabba bar bar Chana cites Rabbi Yochanan that the mother is exempt from future firstborn obligations, but the offspring remains forbidden. The Gemara questions whether a mother would extend mercy to an entirely different species. The inquiry reaches תֵּיקוּ (teiku, it stands unresolved), leaving the offspring's status in doubt.

The Rambam rules that when a creature resembling a pig trails a pregnant cow, the offspring is forbidden due to doubt. Maran codifies this stringency in the Shulchan Arukh: an impure-looking animal found trailing a kosher mother is forbidden as a doubt, lest it was born to an impure animal and merely attached itself to the kosher mother.

אבל אם הניחה מעוברת ואח"כ מצא מין טמא הולך אחריה אף על פי שכרוך אחריה ויונק אותה אסור

But if he left it pregnant and afterward found an impure species walking after it, even though it trails after it and nurses from it, it is forbidden. (Shulchan Arukh, Yoreh De'ah 79:2)

Plucking Wool for Slaughter and Blemish Inspection

The Torah prohibits shearing a בכור (bekhor, firstborn sacrificial animal). A dilemma arises when a person must inspect a blemish on a bekhor or clear space on the neck to perform proper ritual slaughter. The Mishnah cites Rabbi Yosei ben HaMeshullam, who allows clearing wool by uprooting it with a cleaver, provided the hair remains tangled in place. Rav rules in accordance with Rabbi Yosei ben HaMeshullam.

The Gemara extends this discussion to slaughtering ordinary animals on Yom Tov (festival days). On Yom Tov, detaching growth is a prohibited labor. Rav Huna permits clearing wool in the parallel case on Yom Tov.

The Rambam permits plucking wool for slaughter or blemish inspection as long as the wool is not moved from its place. In the Shulchan Arukh, Maran rules that one preparing to inspect or slaughter a bekhor may pluck wool by hand to clear space, but not with a tool, so that it does not appear like shearing. For slaughtering on Yom Tov, Maran rules that one does not intentionally pluck wool, but merely parts it aside by hand.

ודוקא ביד אבל לא בכלי כדי שלא יהא נראה כגוזז

And specifically by hand, but not with an implement, so that it does not appear like shearing. (Shulchan Arukh, Yoreh De'ah 308:3)

Nursing establishes maternal identity to exempt subsequent births, while clearing wool around a firstborn's neck is permitted by hand without an implement.

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